Autumn School on Physics of

Advanced Materials

(PAMS-1)

Iasi 2014

Book of ABSTRACTS

2

Organizers:

11th Carol I Blvd, 700506 Iaşi, Romania

Co-organizers:

RoMS-CGS

3

CONTENTS

Lectures

lecture

(L)

Presenting

author Title page

L1 Stefan Antohe Non-destructive techniques to

investigate the defects in thin films 11

L2 Viacheslav

Barsukov

Promising materials for Li-ion

batteries 12

L3 Shizutoshi

Ando

Preparation and characterization of

ZnS thin films by the chemical bath

deposition method

13

L4 Valentin

Craciun

Growth of multicomponent

amorphous transparent and conductive

oxides by combinatorial pulsed laser

deposition

14

L5 Mikhail

Avdeev

Nanodiamonds in solutions: structural

aspects by small-angle neutron

scattering

15

L6 Abdullah

Yildiz

Carrier transport mechanisms in

metal-oxide thin films 16

L7 M. Kompitsas

Thin film metal oxide electrochemical

gas sensors, functionalized by noble

metal nanoparticles

17

L8 Firuta Borza Amorphous and nanocrystalline

magnetic micro- and nanowires 18

L9 Osman

Adiguzel

Crystal systems and parent-product

structure relation in shape memory

alloys

19

L10 Catalin Martin

Structure and symmetry of the

superconducting gap in Fe-based

superconductors

20

L11 Peter Sloan

Atomic manipulation with the

scanning tunnelling microscope: how

to play with atoms

21

L12 Kathrin Müller Photoelectron spectroscopy to 22

4

investigate chemical, electronic and

structural properties of surfaces

L13 Marco Lattuada Physicochemical properties of

nanoparticles suspensions 23

L14 Regis YN

Gengler

Hybrid functional thin films grown by

a modified Langmuir Blodgett method 24

L15 Vincenzo

Buscaglia

Engineering the phase transitions in

barium titanate: fundamental

strategies and application in multilayer

ceramic capacitors

25

L16 Alexander

Pikulin

Direct laser writing by multi-photon

polymerization: fundamentals and

theoretical concepts

26

L17 Oana Raita What EPR tell us about the spin

dynamics in nanostructured materials? 27

L18 Isabelle

Berbezier

Morphological evolution of SiGe

layers in epitaxy on Si substrate

during MBE growth

28

Student’s posters

Poster

(Ps)

Presenting

author Title page

Ps1 Liliana M.

Trinca

Transparent oxides for electronic

applications 29

Ps2 Ilona Senyk, Super-pure graphite materials and

methods for their purification 30

Ps3 Olena

Ustavytska

Oxygen reduction nanocomposite

electrocatalysts based on conjugated

polymers (polyphenylenediamines,

polyindole) with cobalt

31

Ps4 R. Stanculescu The role of porosity on the functional

properties of BaSrTiO3 ceramics 32

Ps5 Olena

Tynkevych

Temperature-dependent band gap

variation in CdTe–CdS core–shell

quantum dots

33

Ps6 Claudia Catalytical removal of relevant 34

5

Nadejde pollutants from waters using

nanocatalysts

Ps7 Marcela-Corina

Rosu

Ag/TiO2 nanoparticles embedded into

pectin-allantoin-glycerol matrix as

promising UV photoprotective

systems

36

Ps8 Constantin

Lefter

Charge transport phenomena in

molecular spin crossover compounds 37

Ps9 Catalin Palade Effects produced by bismuth

irradiation on high resistivity silicon 39

Ps10 Eduard

Sebastian Barca

Nanostructured powders elaboration

by spvd (solar physical vapor

deposition)

40

Ps11 Maria Andries

The influence of magnetic

nanoparticles on the oxidative activity

in cellulolytic fungi

41

Ps12 Emil Puscasu

Stable colloidal suspension of

magnetite nanoparticles for

applications in life sciences

42

Ps13 Geanina Laura

Pintilei

The influence of Al2O3 and TiO2

deposited coatings to the behavior of

an aluminum alloy subjected to

mechanical shock

43

Ps14 Gabriel Oanca

The preparation and the

characterization of some water-based

ferrofluids

44

Ps15 Vasile-Adrian

Surdu

10 mol% YSZ ceramics and

composites synthesis, characterization

and electric properties

45

Ps16 Rozina

Steigmann

Electromagnetic investigation of

carbon fiber reinforced plastics 46

Ps17 Vlad Preutu

Investigation of composites based on

Poly–ε–caprolactone and

magnetic/ferroelectric nanoparticles

47

Ps18

Carmen -

Mariana

Popescu

Morphological changes in metallic

core/polymer shell nanostructures at

the interaction with physiological

48

6

media

Ps19 Gigel Gicu

Nedelcu

Structural and magnetic properties of

superparamagnetic magnetite

nanoparticles superficially isolated

with biocompatible polymers

49

Ps20 Joana Lancastre

The inorganic oxide network

microstructure in Si based ormosils

prepared by gamma radiation

50

Ps21 Daniel Florin

Sava

Synthesis of nanomaterials with

potential application in sensitized

solar cell

51

Ps22 Aurelian

Carlescu

Magnetoresistance behavior in

thermally treated organic spin valve 52

Ps23 Anton Smirnov The model for laser annealing of non-

linear crystals 53

Ps24 Constantin

Virlan

Photocatalytic evaluation of ferrite

nanoparticles synthesized in palm oil 54

Ps25 Stefan Ionita

Structural investigation of surface and

biological properties of some

composite resins for dental

reconstruction

55

Ps26 Mihaela Toma

Structural investigation of Ni- and Co-

doped ZnO thin films grown by spin

coating

56

7

COMMITTEES

ICPAM-10 and PAMS-1 Chairs

Felicia IACOMI - Faculty of Physics, Alexandru Ioan Cuza University of

Iasi, Romania

Valentin CRACIUN - National Institute for Laser, Plasma and Radiation

Physics, Magurele, Romania

ICPAM-10 and PAMS-1 Session Chairs

Isabelle BERBEZIER - IM2NP - CNRS, University Paul Cézanne,

Marseille, France

George G. RUSU - Alexandru Ioan Cuza University of Iaşi, Romania

Nicoleta LUPU - National Institute of Research & Development for

Technical Physics, Iasi, Romania

Emmanuel KOUDOUMAS - Technological Educational Institute of

Crete, Greece.

Marco LATTUADA - Adolphe Merkle Institute, University of Fribourg,

Switzerland.

Nikita BITYURIN - Institute of Applied Physics, Russian Academy of

Sciences, Russia Nizhnii Novgorod, Russia.

Masaaki NAGATSU - Graduate School of Science and Technology,

Shizuoka University, Hamamatsu, Japan.

Kathrin MUELLER - Zernike Institute of Advanced Materials University

of Groningen, The Netherlands.

Cris ORFESCU - NanoArt 21, Los Angeles, California, US.

Viacheslav BARSUKOV - Department for Electrochemical Power

Engineering & Chemistry, Kiev National University of Technologies and

Design, Ukraine.

Mikhail AVDEEV - Joint Institute for Nuclear Research, Dubna, Russia.

Abdullah YILDIZ - Yildirim Beyazit University, Ankara, Turkey.

Simion SIMON - Faculty of Physics, Babes - Bolyai University, Cluj-

Napoca, Romania

Stefan ANTOHE - Faculty of Physics, University of Bucharest,

Bucharest, Romania

Cristian BABAN - Alexandru Ioan Cuza University of Iaşi, Romania

Liviu LEONTIE - Alexandru Ioan Cuza University of Iaşi, Romania

8

Organizing committee

Shizutoshi ANDO – Tokio University of Science, Tokio, Japan

Aytunç ATES – Yildirim Beyazit University, Ankara, Turkey

Cristian BABAN – Alexandru Ioan Cuza University of Iaşi, Romania

Pascal BALDI – University of Nice Sophia Antipolis, Nice, France

Rozsa BARANYAI – Centre for Energy Research, Hungarian Academy of

Sciences, Budapest Neutron Center, Hungary

Florin BRANZA – Alexandru Ioan Cuza University of Iaşi, Romania

Güven ÇANKAYA – Yildirim Beyazit University, Ankara, Turkey

Dorina CREANGA – Alexandru Ioan Cuza University of Iaşi, Romania

Mircea CRISAN – Alexandru Ioan Cuza University of Iaşi, Romania

Richard CROSS – EMTERC, De Monfrot University, Leicester, UK

Aura DARIESCU – Alexandru Ioan Cuza University of Iaşi, Romania

Ioan DUMITRU – Alexandru Ioan Cuza University of Iaşi, Romania

Cristian FOCSA – Université des Sciences et Technologies de Lille,

France

Paul GASNER – Alexandru Ioan Cuza University of Iaşi, Romania

Silviu GURLUI – Alexandru Ioan Cuza University of Iaşi, Romania

Fahrettin GOKTAS – Yildirim Beyazit University, Ankara, Turkey

Nickolaos KATSARAKIS – Technological Educational Institute of Crete,

Heraklion, Greece

Liviu LEONTIE – Alexandru Ioan Cuza University of Iaşi, Romania

Diana MARDARE – Alexandru Ioan Cuza University of Iaşi, Romania

Cathy PAITEL – IM2NP, Université Aix-Marseille et Sud Toulon Var,

France

Sebastian POPESCU – Alexandru Ioan Cuza University of Iaşi, Romania

Munizer PURICA – National Institute of Research & Development for

Microelectronics, Bucharest, Romania

George G. RUSU – Faculty of Physics, Alexandru Ioan Cuza University of

Iasi, Romania

Iulia SALAORU – Southampton Nanofabrication Centre, Faculty of

Physical Sciences and Engineering, University of Southampton, UK

Adriana SAVIN – National Institute of Research & Development for

Technical Physics, Iaşi, Romania

Mirela SUCHEA – Alexandru Ioan Cuza University of Iaşi, Romania

Daniel TAMPU – Petru Poni Institute of Macromolecular Chemistry, Iaşi,

Romania

9

Sorin TASCU – Alexandru Ioan Cuza University of Iaşi, Romania

Romulus TETEAN – Babes-Bolyai University, Cluj-Napoca, Romania

Lee WHEATLEY – Science Photography, Image Source UK

Advisory committee

Metin AKTAS – Yildirim Beyazit University, Ankara, Turkey

Marco ABBARCHI – University Paul Cézanne, Marseille, France

Marc De MICHELI – University of Nice Sophia Antipolis, Nice, France

Christian BERNHARD – University of Fribourg, Switzerland

Mircea CHIPARA – Indiana University, Bloomington, Indiana, US

Horia CHIRIAC – National Institute of Research and Development for

Technical Physics, Iaşi, Romania

Ciprian DARIESCU – Alexandru Ioan Cuza University of Iaşi, Romania

George KIRIAKIDIS – Institute of Electronic Structure and Laser (IESL),

Foundation for Research and Technology, University of Crete, Heraklion,

Greece

Serafettin EREL – Yildirim Beyazit University, Ankara, Turkey

Chantal FONTAINE – Laboratoire d’Analise et d’Architecture des

systemes-CNRS, Toulouse, France

Violeta GEORGESCU – Alexandru Ioan Cuza University of Iaşi, Romania

Domenico GRIMALDI – Università degli studi della Calabria, Cosenza,

Italy

Janez GRUM – Faculty of Mechanical Engineering, University of

Ljubljana, Slovenia

Igor EVTODIEV – State University of Moldova, Chişinău, Moldova

David HUI – University of New Orleans, US

Prashant N. KUMTA – University of Pittsburg, Pittsburg, US

Dumitru LUCA – Alexandru Ioan Cuza University of Iaşi, Romania

Cornel MUNTEANU – Gheorghe Asachi Technical University, Iaşi,

Romania

Alfonso NASTRO – Università degli studi della Calabria, Cosenza, Italy

Maria NEAGU – Alexandru Ioan Cuza University of Iaşi, Romania

Shashi PAUL – EMTERC De Montfort University, Leicester, U.K.

Florentin PALADI – State University of Moldova, Chişinău, Moldova

Efstathios POLYCHRONIADIS – Aristotle University of Thessaloniki,

Greece

Antoine RONDA – Institut Materiaux Microelectronique Nanosciences de

Provence, Universités Aix-Marseille et Sud Toulon Var, France

10

Gheorghe I. RUSU – Alexandru Ioan Cuza University of Iaşi, Romania

Bogdan C. SIMIONESCU – Petru Poni Institute of Macromolecular

Chemistry, Iaşi, Romania

Alexandru STANCU – Alexandru Ioan Cuza University of Iaşi, Romania

Fernanda Maria Amaro MARGAÇA – Instituto Superior Técnico, Centro

de Ciências e Tecnologias Nucleares, Lisbon, Portugal

Local organizing committee

Cătălin ADOMNIŢEI – Alexandru Ioan Cuza University of Iaşi, Romania

Maria ANDRIES - Alexandru Ioan Cuza University of Iaşi, Romania

Andreea-Georgiana BULAI - Alexandru Ioan Cuza University of Iaşi,

Romania

Marius M. CAZACU - Alexandru Ioan Cuza University of Iaşi, Romania

Aurelian CARLESCU – Alexandru Ioan Cuza University of Iaşi, Romania

Petronela DORNEANU – Petru Poni Institute of Macromolecular

Chemistry, Iaşi, Romania

Dragoş DUTU - Alexandru Ioan Cuza University of Iaşi, Romania

Nicoleta IFTIMIE - National Institute of Research & Development for

Technical Physics, Iaşi, Romania

Stefan IONITA - Alexandru Ioan Cuza University of Iaşi, Romania

George KENANAKIS - Technological Educational Institute of Crete,

Estavromenos Iraklio Crete, Greece

Otilia LEOBA - Alexandru Ioan Cuza University of Iaşi, Romania

Gigel NEDELCU - Alexandru Ioan Cuza University of Iaşi, Romania

Valentin NICA - Alexandru Ioan Cuza University of Iaşi, Romania

Iosif Iulian PETRILĂ – Alexandru Ioan Cuza University of Iaşi, Romania

Daniela Angelica PRICOP - Alexandru Ioan Cuza University of Iaşi,

Romania

Emil PUŞCAŞU - Alexandru Ioan Cuza University of Iaşi, Romania

Alicia Petronela RAMBU - Alexandru Ioan Cuza University of Iaşi,

Romania

Alina SOROCEANU - Petru Poni Institute of Macromolecular Chemistry,

Iaşi, Romania

Cristian STELEA - Alexandru Ioan Cuza University of Iaşi, Romania

Mihai TOMA - Alexandru Ioan Cuza University of Iaşi, Romania

Florin TUDORACHE - Alexandru Ioan Cuza University of Iaşi, Romania

Ioana-Laura VELICU – Alexandru Ioan Cuza University of Iaşi, Romania

11

L1 Non-destructive techniques to investigate the defects in thin films Stefan Antohe

Electricity, Solid State and Biophysics, University of Bucharest, Faculty of Physics,

405 Atomistilor,

P. O. Box MG-11, 077125, Magurele, ILFOV, Romania

The Current-Voltage (I-V) characteristics of the Space-Charge-Limited-

Currents (SCLC), change as a function of density and distribution of the

defects into the Band-Gap (BG) of the semiconductor. Knowing the analytical

relationships of the SCLC I-V characteristics for different trap distributions,

the intrinsic and extrinsic charge carrier transport parameters could be

determined by fitting of the measured I-V characteristics with these analytical

relationships. More quantitative information on the defects present into BG of

a semiconductor can be achieved from Termo Stimulated Currents (TSC)

spectra analysis, too. As example of the application of these defect

investigation techniques, the electrical properties of the non-irradiated and

electron irradiated structures, containing polycrystalline thin layers of CdS

and CdSe, were investigated. The current-voltage characteristics, recorded at

temperatures in the range 150÷400 K, showed that the Ohm’s law is followed

at low-applied voltages, in both non-irradiated and irradiated CdS and CdSe

layers. In the range of high-applied voltages, the space-charge-limited-current

(SCLC), controlled by different types of trap distribution, placed in the band

gape of the semiconducting layer, and has been identified as the dominant

conduction mechanism. An analysis in the frame of SCLC theory allowed us

to obtain the parameters characterizing the trap distributions and the changes

induced by electron irradiation. For a better accuracy other techniques like

TSC, Photoconduction spectra were used to characterize the irradiation

induced defects. The parameters characterizing all the detected traps were

determined.

12

L2 Promising materials for Li-ion batteries Viacheslav Barsukov, Volodymyr Khomenko, Irina Makyeyeva

Electrochemical Power Engineering & Chemistry, Kyiv National University of

Technologies and Design, Kiev, Ukraine

The more popular negative active material for lithium-ion batteries (LIBs)

is usually flake graphite due to its excellent cycle life and low price. The main

disadvantage of graphite is a relatively low specific capacity limited by the

theoretical value Q = 372 mA×h/g. Si, Sn, Al, and some other materials are

the alternate materials for LIBs. However, they have not received a practical

application, since their large theoretical capacity is accompanied by sharp

drop of capacity during the first few cycles. We have formulated the

theoretical principles [1, 2] and developed some experimental composite

anode materials, which give possibility to reach a high level of capacity (ca

600 mA×h/g) during the stable cyclization. Our team has an experience in

synthesis and characterization of positive composite carbon materials, based

on the mixed oxides, as well as Fe phosphate. These materials can ensure

quite high specific capacity, safety and acceptable price for LIBs. Different

new types of electrolytes, polymer binders and separator materials also have

been analyzed. We have developed a new lithium-ion battery technology that

is more powerful than existent for comparable batteries. The improvement of

lithium-ion batteries have been achieved due to advantage of the electrode

specifications and novel nano-materials.

[1] V. Khomenko, V. Barsukov, J. Doninger, I. Barsukov, J. Power Sources, 165/2 (2007) 598-

608.

[2] V. Khomenko, V. Barsukov, Electrochimica Acta, 52, No 8 (2007) 2829-2840.

13

L3 Preparation and characterization of ZnS thin films by the chemical

bath deposition method Shizutoshi Ando

Department of Electrical Engineering, Faculty of Engineering, Tokyo University of

Science,

6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan

Type II-VI semiconductors have long been developed as materials for

optoelectronics. Recently, type II-VI semiconductors have also been

employed in the buffer layer of Cu(In,Ga)Se2 (CIGS) thin-film solar cells.

The chemical bath deposition (CBD) method is one of the growth of thin film

by wet process. Furthermore, this method is a simple apparatus for the

deposition of thin film, and the equipment used has a lower cost compared

with sputtering, and vacuum evaporation which are dry process used for a

mass production line. In recent years, extensive research has been conducted

on CIGS-based thin film solar cells. These thin film solar cells have achieved

conversion efficiencies exceeding 20%, with many using CdS thin films

prepared by CBD. However, CdS thin films contain Cd, which has a large

impact on the environment. Research has therefore been conducted on using

ZnS thin films as the buffer layer in these thin film solar cells with the aim of

further increasing efficiency while improving environmental friendliness.

CIGS-based thin film solar cells that use a ZnS thin film prepared by CBD

(CBD-ZnS) have achieved conversion efficiencies of over 18% [2]. It is

anticipated that the conversion efficiencies of these thin film solar cells will

be increased by improving the crystallinity of the CBD-ZnS thin films. In this

study we investigated three types of temperature profile processes with regard

to the CBD deposition method and trial-manufactured CBD-ZnS thin film

with good crystallinity. In addition, we aimed to establish conditions for

deposition. Improved crystallinity was therefore expected by annealing of

CBD-ZnS thin films fabricated using this thin film growth method, and the

effectiveness and annealing parameters were investigated. ZnSO4 and ZnI2

were used as Zn source materials and thiourea [SC(NH2)2] was used as the

sulfur source material. In addition, aqueous ammonia (NH4OH) was used as

the complexing agent, with pure water used as the solvent. Quartz (SiO2) and

SnO2/glass plate were used as the substrate for growing the films.

[1] Miguel A. Contreras, K. Ramanathan, J. AbuShama, F. Hasoon, D.L. Young, B. Egaas and

R. Noufi, Proc. Photovolt. 13 (2005) 209.

[2] T. Nakada and M. Mizutani, Jpn. J. Appl. Phys. 41 (2002) L165.

14

L4 Growth of multicomponent amorphous transparent and

conductive oxides by combinatorial pulsed laser deposition G. Socol1, E. Axente1, J. Hermann2, A. C. Galca3, D. Pantelica4, P. Ionescu4,

N. Becherescu5, C. Martin6, E. Lambers7, and V. Craciun1

1National Institute for Lasers, Plasma and Radiation Physics, Măgurele, Romania 2LP3, CNRS - Aix-Marseille University, Marseille, France

3 National Institute for Materials Physics, Măgurele, Romania 4Horia Hulubei National Institute for Physics and Nuclear Engineering, Măgurele,

Romania 5Appel Laser, Bucharest, Romania

6Ramapo College of New Jersey, NJ, USA 7MAIC, University of Florida, Gainesville, USA

In this presentation we focus on the relationship between composition and

properties of IZO and IGZO thin films synthesized using the Combinatorial

Pulsed Laser Deposition technique. An accurate monitoring of the thin films

elemental composition was performed by Laser-Induced Breakdown

Spectroscopy (LIBS) based on plasma modeling in view of further in-situ and

real-time technological developments and process control in case of ASOs

fabrication. The cation fractions measured by LIBS were compared to values

obtained by complementary measurements using Rutherford backscattering

spectrometry, energy dispersive X-ray analysis and X-ray fluorescence.

The optical properties (thickness profile and refractive index determination)

of the thin films were inferred from spectroscopic ellipsometry data acquired

in the visible range and optical reflectance measured from 30 cm-1 (4 meV) to

30 000 cm-1 (4 eV). Complementary investigations to obtain the thickness and

density of the deposited films as well as their surface and interface roughness

have been performed by fitting the measured X-ray reflectivity and X-ray

diffuse scattering curves with simulated ones using dedicated models. The

room temperature electrical properties were investigated using typical four-

point probe geometry and Hall measurements and compared with the values

estimated from the optical reflectance data. X-ray photoelectron spectroscopy

was used to measure the energy discontinuities in the valence and conduction

bands of various dielectric/IGZO and dielectric/IZO heterostructures. All

these measurements helped design better transparent and conductive oxides

containing lower amounts of In, an element that is rather scarce and therefore

expensive.

15

L5 Nanodiamonds in solutions: structural aspects by small-angle

neutron scattering Mikhail Avdeev

Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna,

Russia

Detonation nanodiamond (DND) particles attract increasing attention as a

promising nanomaterial due to its biocompatility, ability to penetrate the cell

membrane, and easy functionalization and conjugation with biomolecules.

The synthesis of stable in time and concentrated aqueous dispersions of DND

shows a significant progress in recent years. The presence of liquid

homogeneous media in such systems makes it possible to apply rather

effectively the small-angle neutron scattering (SANS) to clarify some

important structural aspects of the inner particle structure and particle

interaction. SANS experiments from DND solutions (concentration range of

1-10%) from different producers reveal a strong effect of aggregation. The

large aggregates (mean size above 120 nm) are characterized by a developed

organization with fractal dimension D ~ 2.3-2.5, thus pointing out a common

mechanism of a diffusion limited cluster–cluster aggregation. They can

interpenetrate each other when concentrating the system, which determines a

gel transition in the systems. Small clusters are compact and interact by the

‘hard-sphere repulsion’ mechanism. The particles composing the aggregates

(DND particles) show a complex inner structure corresponding to a rather

wide spatial diamond-graphite transition within the particles (in terms of

averaged radial density profile). This transition is reflected in the formation of

the diffusive interface on the particle surface, which can be well described

using the data of SANS contrast variation experiments. In addition to the

characteristics of the transition, the parameters of the DND particle size

distribution function are obtained.

[1] M. V. Avdeev, et al., J. Phys. Chem. C 113 (2009) 94,

[2] M. V. Avdeev, et al., J. Phys. Cond. Matter 25 (2013) 445001

[3] O. V. Tomchuk, et al., J. Appl. Cryst. 47 (2014) 642

16

L6 Carrier transport mechanisms in metal-oxide thin films Abdullah Yildiz

Faculty of Engineering and Natural Sciences, Yıldırım Beyazıt University, Ankara,

Turkey

Recently, there have been several attempts to understand the outstanding

electrical transport properties of metal oxide films. The analysis of carrier

transport properties of these materials is always difficult and controversial.

There are several models explaining carrier transport behavior of metal oxide

films. These models are simple thermal activation process (Arrhenius law),

single phonon-assisted Mott type variable-range hopping (Mott-VRH), single

phonon-assisted Efros-Shklovskii type variable-range hopping (ES VRH),

adiabatic small polaron hopping (A-SPH), non-adiabatic small polaron

hopping (N-SPH), multiphonon hopping (MPH), thermionic emission (TE)

and tunneling (TN) grain boundaries (GBs) conductions, Meyer-Neldel Rule

(MNR), metallic conduction (MC), electron-electron interactions (EEI), weak

localization (WL) and anti-weak localization (AWL) models. Depending on

some parameters such as the employed temperature range, Bohr radius, band

gap, crystal structure, and degrees of disorder in the investigated film, one can

expect that one or more than one of these models hold. A clear transition from

a conduction mechanism to another may be also observed. This study reviews

and evaluates the carrier transport mechanisms of various metal-oxide

materials such as ZnO, SnO2, TiO2, In2O3, and CuO.

17

L7 Thin film metal oxide electrochemical gas sensors, functionalized

by noble metal nanoparticles M. Kompitsas1, M. Kandyla1, P. Koralli1,2, G. Mousdis1

1National Hellenic Research Foundation, Theoretical and Physical Chemistry

Institute, Athens,

48 Vasileos Constantinou Avenue, 11635 Athens, GREECE 2School of Mechanical Engineering, National Technical University of Athens, Athens,

Iroon Polytechniou 9 Zografos, 15780 Athens, GREECE

Electrochemical gas sensors are those that their conductivity changes, when

they react with a gas. Today, semiconducting metal oxide (SC-MO) thin films

form a special class of gas sensors that are portable, cheap, consume low

power and are characterized by high sensitivity and stability. Most of the

sensor developments concerned n-type MO films and thus they mainly

occupy the market today. Less p-type SC-MO films are known (NiO, CuxO,

CoO), and show generally less gas sensitivity. During the last 10 years,

intensive work has started on p-type gas sensors development. Various

growth techniques have been applied, such as sol-gel, sputtering, spray

pyrolysis, pulsed laser deposition (PLD) a.o. To account for the low

sensitivity, noble metal nanoparticles (Au, Pd, Pt) have been either embedded

into the film matrix during growth or used to partially cover the film surface

in a post growth process. Independent of the type of growth and

functionalization, such MO-noble metal nano-compounds have shown

increased sensitivity and faster response, when tested against hydrogen/air

mixtures, down to a few ppm and at low temperatures. Currently, sensing

characteristics are optimized by controlling the concentration of the noble

metal in the compound. The efficiency of a gas sensor is given by the so-

called 3S criterion: Stability-Sensitivity-Selectivity. In particular selectivity is

a critical aspect if a sensor is surveying a complex gas environment. Such

problems are solved by using sensor arrays that are educated by neural

networks to respond only to one gas type. The simplest array may consist of

two sensors. For example, an n-type (ZnO) and a p-type (NiO) thin film

sensor, when tested against the reducing hydrogen gas, show an increase and

decrease of the conductivity, respectively. Thus, oxidizing and reducing gases

can be easily distinguished.

18

L8 Amorphous and nanocrystalline magnetic micro- and nanowires Firuta Borza

Magnetic Materials and Devices, National Institute of Research & Development for

Technical Physics, Iasi, Romania

Amorphous magnetic wires have been available for more than two decades

and research on these materials has been established in many laboratories

throughout the world. The group in the National Institute of Technical

Physics, Iasi has performed pioneering work in the preparation and

characterisation of wire-shaped amorphous and nanocrystalline materials

since 1990s in both “in rotating water quenched” and “rapid drawing from the

melt in glass coating” wire systems with typical diameters ranging from

hundreds to several micrometers. Recently, the technological limits of the

glass-coated melt spinning method were pushed beyond those used for the

production of glass-coated microwires and thus, the diameters of microwires

has been drastically reduced down to hundreds of nanometers. Due to

combined strong directional physical properties, unique magnetoelastic

interactions, magnetic structure, and specific interphase interactions magnetic

wires exhibit a diverse range of physical effects (large Barkhausen

discontinuity, fast domain-wall (DW) propagation, and giant

magnetoimpedance (GMI) at MHz frequencies). The current interest in

microwires includes: (i) the opportunity of processing novel wire systems of

various compositions and geometry, (ii) basic studies on micromagnetics of

the magnetization reversal process (particularly in wires with a single domain

wall) and its dynamics, (iii) high-frequency studies on GMI and ferromagnetic

resonance, showing quite interesting properties at MHz and GHz frequencies,

and (iv) technological applications mostly as sensing elements in various

devices and recently in smart materials. There are two main magnetic features

of microwires that make them attractive for applications namely, their bistable

behavior and their magnetoimpedance response, but other interesting

applications are based on the magnetoelastic effect and stress-impedance

effects. The unique properties and cost effective preparation process of glass-

coated amorphous nanowires makes them good candidates in spintronics

applications. Acknowledgements- Work supported by the Romanian Ministry of National Education,

under project SMARTFLOW (Theme PN-II-PT-PCCA-2013-4-0471).

19

L9 Crystal systems and parent-product structure relation in shape

memory alloys Osman Adiguzel

Department of Physics, Firat University, Elazig, Turkey

Crystals are characterized by regular arrangement of atoms or molecules

and consist of periodic arrangements of atoms, and each repeating unit is the

unit cell. Each unit cell has a geometric structure, and different lattice systems

are created by varying the lattice parameters; a, b and c, and the angles, a, b

and g. Considering the geometric structures, seven crystal systems are

obtained, and all the seven lattice systems have a total of 14 crystal structures.

Directions are defined in real space, and crystal planes are described with

Miller indices in reciprocal space. In the determination of crystal structure, x-

ray and electron diffractions are mainly used. Diffraction is an action of the

interference of the diffracted rays from the parallel crystal planes. The

systematic rules of x-ray diffraction are Bragg’s Law and structure factor,

F(hkl). Alloys are composed of two or more types of elements, and have

different phases, depending on the alloy composition. Heat treatment is

important factor in the formation of stable and metastable phases, and the

change in the microstructure is called phase transition or phase

transformation. A series of alloy systems exhibit a peculiar property called

shape memory effect based on a solid state phase transformation, martensitic

transformation. Martensitic transformations are first order phase

transformations and occur with cooperative movement of atoms by means of

lattice invariant shears in materials on cooling from high temperature parent

phase region. Experimental studies were performed on two ternary copper

based alloys; CuZnAl and CuAlMn. Simulation studies were performed on a

molecular dynamics cell (MDC) of NiAl alloy model using molecular

dynamics (MD) simulation technique. Two molecular dynamics (MD)

simulation methods which allow the system to vary in shape and size was

used. For this purpose, square molecular dynamics cells (MDC) of 216 B2

unit cells which include 432 atoms have been constructed. The molecular

dynamics cell (MDC) has been cooled and heated in a temperature interval,

700K-350K. Sutton-Chen and Lennard-Jones potential energy functions have

been adopted to explain how the potential energy functions affect the

transformation mechanism.

J. MA. I. Karaman and RD. Noebe, International Materials Reviews 55, 257, 2010.

O. Adiguzel, Journal of Materials Processing Technology 185, 120, 2007.

S. Ozgen, O. Adiguzel, J. Physics and Chemistry of Solids 65,861, 2004.

20

L10 Structure and symmetry of the superconducting gap in Fe-based

superconductors Catalin Martin1, V. G. Kogan2, M. Tanatar2, N. Ni2, A. Diaconu3, L. Spinu3, D. B.

Tanner4, P. C. Canfield2, R. Prozorov2 1Engineering Physics, Ramapo College of NJ, Mahwah, USA

2Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, USA 3Advanced Materials Research Institute, University of New Orleans, New Orleans, USA

4Physics, University of Florida, Gainesville, USA

The recent discovery of superconductivity in iron arsenide compounds,

with the highest critical temperature exceeding Tc = 50 K, has reignited the

interest in the field. Advance in crystal growth techniques, characterization

tools and computational methods have allowed the exploration of these new

superconductors at an almost unprecedented rate. Several related classes of

materials were synthesized within less than one year and their electronic

properties were determined both theoretically (via band structure calculations)

and experimentally, almost at the same time. Despite all these rapid

developments, fundamental questions, like the mechanism for pairing, or the

structure and symmetry of the superconducting gap, are still debated today. In

this lecture, I will give an overview of Fe-based superconductors and discuss

the evolution of our understanding of the pairing mechanism and of the

structure of the superconducting gap. A detailed study of high sensitivity

penetration depth experiments will be presented and discussed, in connection

with other experimental methods and with theoretical predictions. I will make

the case that the superconducting gap is highly anisotropic, and even nodal, in

many of these compounds. Additionally, optical conductivity data will be

involved, arguing for possible electronic inhomogeneity in some of the Fe-

based compounds, which affects experimental measurements and complicates

the understanding of the superconducting properties in these materials.

C. Martin et al., Phys. Rev. B, 81 060505(R) (2010)

C. Martin et al., Supercond. Sci. Technol., 23, 065022 (2010)

C. Martin et al., Phys. Rev. Lett., 102, 247002 (2009)

21

L11 Atomic manipulation with the scanning tunnelling microscope:

how to play with atoms Peter Sloan

Department of Physics, University of Bath, Bath, UK

The ultimate building blocks of matter are atoms and molecules. If we

can control these we can truly build from the bottom up, for example, a

computer made of atomic-scale components that would fit into the palm of

your hand, yet would be more powerful than today's supercomputers. In 1986

the Nobel prize was won for the scanning tunneling microscope (STM) which

can image individual atoms. In 1989 this microscope was used to assemble,

atom-by-atom, the world’s first ever atomically precise structure (a tiny advert

for IBM). So why, in the intervening 23 years, has such atomic scale

engineering not become commonplace in modern technology? In this talk I

will review what can be done at the single molecule level, for example,

breaking or making individual chemical bonds, adding a single electron to a

single gold atom, constructing a molecular transistor, constructing molecular

logic gates. All these are beautiful examples of the power of single molecule

science, but are strictly one-atom-at-a-time methods of construction. This

leads to a fundamental manufacturing bottleneck with resulting lengthy and

tedious construction of anything but the simplest structure. I conclude by

showing a possible solution where we extend the control of the microscope

from one atom to many.

22

L12 Photoelectron spectroscopy to investigate chemical, electronic and

structural properties of surfaces Kathrin Müller

Zernike Institute for Advanced Materials, University of Groningen, Groningen, The

Netherlands

Photoelectron spectroscopy (PES) is one of the most versatile techniques

to study surfaces and interfaces due to its high surface sensitivity and

flexibility. In this lecture I will review several different PES techniques like x-

ray photoelectron spectroscopy (XPS), angle-resolved photoelectron

spectroscopy (ARPES) and normal incidence x-ray standing waves (NIXSW).

XPS is one of the most often used techniques to investigate chemical

composition of surfaces and interfaces, because it is specific to the elemental

and chemical composition and it can be used to quantify the surface

composition. While for XPS core-hole electrons are analyzed ARPES is used

to measure valence electrons. Thus, it is specific to the occupied electronic

bands and can be used to get a map of the electronic band structure in the

reciprocal space. NIXSW uses the constructive or destructive interference of

the incoming and outgoing high energy photons the distance of adsorbates

with respect to the surface can be mapped. Besides explaining the

experimental set-ups and basic physical principles I will also show several

illustrative examples on how these techniques are used in modern surface

science in order to characterize surface properties.

23

L13 Physicochemical properties of nanoparticles suspensions Marco Lattuada

University of Fribourg, Adolphe Merkle Institute, Marly, Switzerland

Many nanoparticles, independently of their preparation, need to be

dispersed in suitable solvents. The so-obtained colloidal dispersions have

many unique properties, mostly a consequence of the particles small size and

high specific surface. In this lecture, the most important physicochemical

properties of dispersions will be reviewed. These include the typical

mechanisms responsible for particles dispersion, i.e., Brownian motion, and

shear forces. Then the concept of colloidal stability will be addressed. Since

colloidal stability is an essential feature of colloidal dispersions, the main

interparticle forces involved in determining particles stability will be

reviewed. These include Van der Waals forces, electrostatic interactions and

steric forces. The fate of unstable colloidal suspensions and aggregation

kinetics will also be addressed.

24

L14 Hybrid functional thin films grown by a modified Langmuir

Blodgett method Regis YN Gengler

Zernike Institute For Advanced Materials, University of Groningen, Groningen, The

Netherlands

This tutorial will report on a new method based on the use of Langmuir-

Schaefer deposition for the creation of functional nano-materials. The

fundamental principle of this simple, but yet powerful method will be

explained. Successful examples of the use of this hybrid method for the

creation of high electronic quality reduced graphene oxide and exfoliated

graphene films will be presented. Examples of the combination of the

aforementioned method with self-assembly will also be shown. That

combination allowed the creation of hybrid organic-inorganic nanostructures

for magnetism: insert of highly anisotropic Ni(8) magnetic molecules,

creation of Prussian Blue analogues of reduced dimensionality and other

photo-switchable magnetic materials. Various example of successful

deposition and creation of functional nanostructured materials will be

presented supported by spectroscopic, crystallographic, and magnetic data.

The described method is thought as a new route toward the highly controlled

fabrication of tailored functional organic-inorganic nanomaterials.

25

L15 Engineering the phase transitions in barium titanate: fundamental

strategies and application in multilayer ceramic capacitors Vincenzo Buscaglia

Institute for Energetics and Interphases, National Research Council, Genoa, Italy

The discovery of BaTiO3 after World War II has transformed

piezoelectric and ferroelectric effects from just a scientific curiosity to a

highly innovative and profitable industry with applications in underwater

sonars, medical imaging, diesel engine injection systems and non-volatile

memories. Owing to the high dielectric constant (of the order 2000-4000) and

the low losses (tan delta about 1%), BaTiO3–based ceramics have also found

application as dielectrics in multilayer ceramic capacitors (MLCCs), the most

widely used passive electronic component in consumer electronics and cars. A

MLCC is basically composed of a stack of dielectric layers separated by

metallic electrodes where the single thin plate capacitors are connected in

parallel. The dielectric layers are fabricated by tape casting of ceramic

slurries, a robust and cheap technology. Despite more than 50 years of

evolution, the MLCC technology is still progressing. The main market trend

is towards miniaturization and the need to achieve higher capacitance in a

smaller volume. Nowadays the top end capacitors can have more than 1000

layers and a dielectric thickness of 0.5 micron. This means that the lateral

dimension of a typical MLCC is no more than 1 mm. Main requirement for

MLCCs is a flat dielectric constant over a typical temperature range of -50 to

150°C. Pure BaTiO3 ceramics are not suitable for this application because of

the strong permittivity variations at the Curie temperature (125°C) and around

room temperature (orthorhombic/tetragonal transition). Therefore, in order to

exploit the excellent dielectric properties of the material, the influence of

doping, formation of solid-solutions, non-uniform dopant distribution and

grain size were extensively investigated. As a result, the permittivity peaks

corresponding to the phase transitions could be shifted, broadened and even

suppressed while maintaining a high dielectric constant (>1000), and many

formulations evolved in commercial products. In this lecture, a general

overview on the engineering of the phase transitions in BaTiO3 ceramics and

on the development of the MLCC technology will be given.

26

L16 Direct laser writing by multi-photon polymerization: fundamentals

and theoretical concepts Alexander Pikulin

Nonlinear Dynamics and Optics, Institute of Applied Physics, Russian Academy of

Sciences, Nizhniy Novgorod, Russia

Multiphoton polymerization is a unique rapid prototyping technique that

allows for submicron spatial resolution in three dimensions. The polymer

micro- and nanostructures can be created by direct writing by a focused

beam of the ultrashort-pulse laser. This lecture will focus mostly on the

fundamentals and the modeling aspect of laser nanopolymerization. Initially,

an overview of the direct laser writing (DLW) technique will be given.

Monte Carlo realizations of polymer voxels

The most up-to-date achievements in this field will be outlined. The goal of

the lecture is to address the peculiarities of the nanoscale polymerization and

discuss the physical mechanisms that determine the spatial resolution and

minimal feature size that can be achieved with DLW.

27

L17 What EPR tell us about the spin dynamics in nanostructured

materials? Oana Raita

Physics of Nanostructured Materials , National Institute for Research and

Development of Isotopic and Molecular Technologies , Cluj-Napoca, Romania

EPR (FMR) spectroscopy is a very sensitive technique to investigate the

incorporation degree of TM ions, detection of the ferromagnetic ordering and

spin dynamics as function of the annealing temperature, dopant concentration

in different advanced materials. The main goal of this work is to investigate

by EPR the effects of: (i) partial substitution with diamagnetic ions at Mn site

(ii) grain size reduction on the exchange coupling integral between Mn spins,

J, and the polaron activation energy, Ea in substituted microstructured and

nanosized manganites, respectively. Also, I will present EPR (FMR)

investigations of Zn(1-x)TM(x)O and Sn(1−x)TM(x)O(2) micro and nano

powders (TM= Mn, Co, Fe) which reveal information about the presence of

the ferromagnetic phase inferred from the shift of the magnetic field position

of EPR line to the lower field and the line broadening as the temperature is

lowered; Evidence of both isolated TM ions located substitutionally at Zn

(Sn) sites and interstitial ones situated on the particle surfaces; The spin

dynamic properties of the samples as evidenced by EPR are very sensitive to

the annealing temperature; The ferromagnetism in Zn(1-x)TM(x)O and

Sn(1−x)TM(x)O(2) appears only in the low-temperature annealed samples.

28

L18 Morphological evolution of SiGe layers in epitaxy on Si substrate

during MBE growth Isabelle Berbezier

IM2NP, CNRS, AMU, Marseille, France

The aim of this lecture is to review the different phenomena observed

during the epitaxy on Silicon starting from the basic concepts (reconstruction,

step edge energy, equilibrium shape, surface energy anisotropy) to describe

the growth modes and regimes as a function of the experimental conditions

(temperature, flux, stress, crystalline orientation). I will also present the

different growth instabilities and discuss their kinetic, thermodynamic or

energetic origin. As an example, the quantitative study of step bunching

instability during the epitaxy of Si/Si(001) vicinal substrates, the

morphological evolution of Si layers and their modeling by kinetic Monte

Carlo simulations will be described. These studies did show the importance of

surface diffusion anisotropy on the atomic steps mobility on Si. The

microscopic origin of this kinetic instability is explained by the different

sticking barriers at the SA and SB steps i.e. in fine by the presence of a pseudo-

inverse Schwoebel barrier. In a second part, the morphological evolution of

epitaxial layers under compressive biaxial stress will be exposed. A particular

attention will be paid to the low strain regime during which the formation of

3D islands by the interrupted coarsening of the Asarro Tiller Grinfeld (ATG)

instability. The compliant effect of specific pseudo-substrates (SOI or porous

silicon in different experimental conditions) on this evolution will be

mentioned. The demonstration of a counter-intuitive effect discovered by

continuum theory modelling (J.N. Aqua) showing the enhanced development

of the instability on a softer substrate will be explained.

29

Ps1 Transparent oxides for electronic applications Liliana M. Trinca1,2, Aurelian C. Galca1, Cristina F. Chirila1, Cristina

Besleaga1, Andra G. Boni1,2, Lucian Pintilie1 1Multifunctional Materials and Structures, National Institute of Materials Physics,

Magurele, Romania 2Condensed Matter Physics, Faculty of Physics, University of Bucharest, Magurele,

Romania

Due to growing needs of the modern human, transparent electronics

become an emerging science and technology field focusing on processing and

developing invisible circuits. There is a global trend to minimize the cost of

the final product-electronic device, starting from raw materials to adaptability

on the currently existing platforms. Zinc oxide (ZnO), a transparent material,

gains a huge interest due to low price and to the possibility to tune the optical

and electrical properties by slightly impurifying. Doping ZnO with Aluminum

(AZO), the semiconductor to metal transition can be achieved (free electrons

concentration of ~ 1020 cm-3) [1]. Short time p-type is achieved by doping

ZnO with Lithium (LZO) [2]; it was also reported that LZO thin films are

ferroelectric [3]. In this work, the technological process of achieving ZnO-

based thin films and multilayer structures starting from raw powders is

presented. Aiming the fabrication of thin film transistors, each layer has been

thoroughly investigated: AZO as transparent electrode and LZO as gate

dielectric (or even ferroelectric). X-ray diffraction, Spectroscopic

Ellipsometry and electrical measurements indicate the proper recipe, and also

give a comprehensive chart which interlinks the physical properties of the thin

films/multilayers.

[1] A. C. Gâlcă et al, Thin Solid Films 518 (2010) 4603.

[2] Sh. Yu et al, Thin Solid Films 540 (2013) 146.

[3] Dhananjay et al, J. Appl. Phys. 101 (2007) 104104.

30

Ps2 Super-pure graphite materials and methods for their purification Ilona Senyk, Volodymyr Lysin, Volodymyr Khomenko, Viacheslav Barsukov

Electrochemical Power Engineering and Chemistry, Kiev National University of

Technologies and Design (KNUTD), Kyiv, Ukraine

Super-pure graphite materials have founded a wide application for lithium-

ion batteries, fuel cells, artificial diamond production and some other key

fields of advanced materials. A row for such material is usually graphite ore,

which contains usually from 5% to 22% of natural graphite. After thorough

pretreatment including multistage flotation process it is possible to reach

intermediate product with carbon content of 95-98%, which is not sufficient

for the high-tech applications. Among the other 2-5% there are usually many

of Fe, Si, Al, Ca, Cu, Ni, Zn, Cr, Mo, W, V and other undesirable admixtures.

There are in essence two main technologies for final purification of graphite:

thermal and chemical. Thermally purified graphite has usually high purity

levels of 99.95-99.98%C, but is very costly due to the high temperatures for

treatment (ca 3000 °C), inert atmosphere (N2 or Ar2) and quite complicated

equipment (furnaces with counter flow). Chemically upgraded natural

graphite is usually available in the low purity levels, but has relatively low

costs. Thus, each route provides own advantages and disadvantages. KNUTD

team has developed few improved chemical purification processes, which

give possibility to reach the high purity level up to 99.98 %C [1]. A strategy

of chemical purification depends strongly on chemical composition and

morphology of graphite after the flotation process. If there are no sufficient

amount of Si and Al, it is possible to use acidic treatment of natural graphite

in 1 stage. If there are many Si and Al, it is necessary to use 3 stage acidic-

alkaline-acidic treatments, or use different combinations of concentrated acids

in 1-2 stages.

1. Chemical method of graphite treatment, Ukrainian patents No 96846 (12.12.2011, Bul. # 23)

and No 98691 (11.06.2012, Bul. # 11).

31

Ps3 Oxygen reduction nanocomposite electrocatalysts based on

conjugated polymers (polyphenylenediamines, polyindole) with

cobalt Olena Ustavytska, Denys Mazur, Yaroslav Kurys

Department of free radicals, L. V. Pysarzhevsky Institute of Physical Chemistry of

National Academy of Sciences of Ukraine, Kyiv, Ukraine

There are two most promising types of non-precious-metal oxygen

reduction reaction (ORR) electrocatalysts based on nitrogen-contaiting

conjugated polymers (CPs): unpyrolyzed carbon-supported metal-polymer

ORR electrocatalysts based on CPs and cobalt as well as so called Me-N-C

catalysts that can be prepared by pyrolysis of CPs (as nitrogen-containing

precursors), different salts of transition metals (Co, Fe, or a combination

thereon) and carbon component. But only polypyrrole (PPy) or polyaniline

(PANI) as a components of such electrocatalysts were reported in literature.

We obtained unpyrolized metal-polymer nanocomposite electrocatalysts

based on amino-substituted analogues of PANI (poly-o-phenylenediamine –

PoPDA, poly-m-phenylenediamine – PmPDA) or structural analogue of PPy

(polyindole – PIn), cobalt, and carbon black, as well as pyrolyzed Co-N-C

catalysts based on the same CPs. Composition, morphology, structure and

electrochemical properties of prepared electrocatalysts were characterized. It

is shown, that such electrocatalysts are capable of exhibiting sufficiently high

activity for the ORR in acidic electrolyte. For example, the activity for ORR

of unpyrolized nanocomposites based on PoPDA or PmPDA (ORR onset

potential, Eonset up to 450 mV; ORR peak potential, Ep up to 245 mV vs.

SHE) are markedly higher than that for previously reported similar PANI-

based composite, which may be due to effective formation and/or increasing

of the number of C/CoNx-sites in electrocatalysts at the expense of the

presence of additional nitrogen atoms in poly(phenylenediamines). It is

established that heat treatment of the nanocomposites leads to a significant

anodic shift of Eonset and Ep values. In particular, pyrolyzed nanocomposite

electrocatalysts based on PIn characterized by Eonset ~ 600 mV and Ep ~ 445

mV (vs. SHE).

32

Ps4 The role of porosity on the functional properties of BaSrTiO3

ceramics R. Stanculescu1, C. E. Ciomaga1, C. Galassi2, L. Mitoseriu1

1Faculty of Physics, Alexandru Ioan Cuza University, Iasi, Romania 2ISTEC-CNR, Via Granarolo, no.64, I - 48018, Faenza, Italy

The purpose of this study was to prepare and to discuss the role of porosity

on functional properties in Ba0.70Sr0.30TiO3 (BST) ceramics with different

degrees of porosity. Powders with this composition were prepared following

the mixed oxide method by solid-state reaction at 950°C calcination

temperature for 4h and the bulk ceramics at 1450°C sintering temperature for

2h. Various porosities of the BST ceramic samples have been obtained by

adding lamellar carbon black in concentration of 10, 20 and 35 vol% as

sacrificial template in the BST powder. The sacrificial template burns out

during the sintering process and this induces modification in the morphology,

microstructure and pore density of the ceramic product. The purity phase of

the obtained BST ceramic was checked by XRD analysis and the

microstructures was observed using Scanning Electron Microscopy (SEM). A

fracture mode transformation from intragranular to an intergranular fracture

has been observed. Modifications of the grain size and of the grain boundaries

volume were also observed and discussed. The density of the investigated

samples, measured by Archimedes method, varies from values around 95%

until 68% of their theoretical value for the dense and porous ceramics. The

effect of addition of carbon black as pore forming agent on the dielectric

response at low and high electric field was investigated and discussed. Using

Impedance Spectroscopy method in the temperature range of (21-200)°C and

frequency of 20Hz–2MHz it was observed the dielectric behavior in the BST

dense and porous ceramics. The experimental results have shown that the

dielectric permittivity of the BST ceramics with different degree of porosity

decrease with increasing the porosity, from around ~ 7500 down to ~ 250, and

present a phase transition from ferroelectric to paraelectric state for a Curie

temperature close to the room temperature (around 30°C).

Acknowledgements: This work was financially supported by CNCS-UEFISCDI project PNII-

RU-TE-2012-3-0150 and by the strategic grant POSDRU/159/1.5/S/137750, Project “Doctoral

and Postdoctoral programs support for increased competitiveness in Exact Sciences research”.

33

Ps5 Temperature-dependent band gap variation in CdTe–CdS core–

shell quantum dots Olena Tynkevych1, Natalia Vyhnan1, Konstyantyn Likhnitski2, Ilona Senyk2,

Viacheslav Barsukov2, Petro Fochuk1, Yuriy Khalavka1 1Department of Inorganic Chemistry of Solid State & Nanomaterials, Yuriy

Fedkovych Chernivtsi National University, Chernivtsi, Ukraine 22Department of Electrochemical Power Engineering & Chemistry, Kiev National

University of Technologies and Design, Kiev, Ukraine

Colloidal semiconductor quantum dots (QDs) have unique size-

dependent chemical and physical properties. Сyclic voltammetry (CV)

measurements of QDs give information about the valence and conduction

bands (from the oxidation/reduction potential values). In this study the

electrochemical band structure of CdTe–CdS core–shell QDs of different

diameter was measured. Also, we investigated the temperature-dependent

optical (ΔEopt) and electrochemical (ΔEcv) band gap variation in CdTe–CdS

core–shell QDs of different diameter stabilized by thioglycolic acid.

Measurements were carried out in the range starting from 293 K to 238 K. PL

spectra were excited by solid-state diode laser (405 nm) and recorded on a

OceanOptics USB-2000 spectrophotometer. Three-electrode system with

platinum or carbon counter electrodes, an Ag/AgCl reference electrode and

the flat platinum electrode as the working electrode was used for the CV

measurements. Scan rate were 0.2, 0.5 and 1 V/s. It was found that distance

between the oxidation and reduction peaks increases with decrease of QDs

size. This trend is consistent with spectroscopic data. However, it should be

noted that the CV band gap energy (ΔEcv) is 0.1 – 0.3 eV smaller than the

optical (ΔEopt) in most cases. A reason for these disagreements may be related

to the oxidation of surface defects forming surface states in the band gap that

act as local trap states. Investigating the temperature-dependent band gap

energy variation (ΔEopt and ΔEcv) shows that the temperature coefficient

decreases with increasing size of the QDs. The temperature dependence of the

electrochemical and optical energy gaps agree well with Varshni equation. This publication is based on the work supported by a grant from the U.S Civilian Research &

Development Foundation (CRDF Global) (UKC2-7071-CH–12), State Agency on Science,

Innovation and Informatization of Ukraine (М/85-2014), and State Fund of Fundamental

Research.

34

Ps6 Catalytical removal of relevant pollutants from waters using

nanocatalysts Claudia Nadejde1, Mariana Neamtu1, R. J. Schneider2, D. V. Hodoroaba2 1Interdisciplinary Research Department – Field Science, Alexandru Ioan Cuza

University, Iasi, Romania 2BAM Federal Institute for Materials Research and Testing , Unter den Eichen 87,

12205 Berlin, Germany

Synthetic reactive dyes are non-biodegradable major sources of water

pollution leading to severe effects on living organisms. In the last years,

magnetic nanostructures based on iron oxides were often the materials of

choice in environmental clean-up technologies [1,2] due to their availability,

low cost and environmentally friendly nature, especially when their surface is

modified with photoactive non-toxic compounds, resulting in highly efficient

materials able to remove recalcitrant organic pollutants from various media.

This study evaluates the catalytic efficiency of a novel magnetically

responsive catalyst for the degradation of two reactive azo dyes, Reactive

Yellow 84 (RY84, 25 mg∙L-1) and Reactive Black 5 (RB5, 12.5 mg∙L-1) using

hydrogen peroxide, as an oxidant, under very mild conditions (atmospheric

pressure and room temperature). The catalysts were prepared by the co-

precipitation method, followed by their complexation with ferrous oxalate

(FeC2O4∙2H2O) in order to enhance the overall magnetic properties of the

nanomaterial. The sensitized nanomaterial was characterized by several

microstructure characterization techniques (X-ray diffraction, vibrating

sample magnetometry, scanning electron microscopy, energy dispersive X-ray

spectroscopy). All experiments were performed on a laboratory scale set-up.

Important variables such as effect of hydrogen peroxide concentration, the

amount of catalyst and contact time for the catalytic wet peroxide oxidation

(CWHPO) of RY84 and RB5 were examined. The best experimental

conditions can be described as pH = 6, T = 25 oC, a catalyst concentration of

10 g/L and 20 mmol/L H2O2. The results show that it is possible to remove

53% in the absence of H2O2 and up to 99.7 % in the presence of 20 mM

hydrogen peroxide after the 240 minutes of oxidation at the above-mentioned

conditions. Catalytic wet peroxide oxidation on sensitized magnetic fluid of

reactive dyes can be a suitable pre-treatment method for complete

decolorization of effluents from textile dyeing and finishing processes, once

the optimum operating conditions are established. Acknowledgement: This work was supported by the CNCS–UEFISCDI through the national

grant type PN-II-ID-PCE-2012-4-0477.

35

1. Xu P., Zeng G.Mi., Huang D.L., Feng C.L., Hu S., Zhao M.H., Lai C., Wei Z., Huang C., Xie

G.X., Liu Z.F., Sci. Total Environ., 2012, 424,1.

2. Vijayaraghavan J., Sardhar Basha S. J., Jegan J.,J. Urban Environ. Eng., 2013, 7, 30.

36

Ps7 Ag/TiO2 nanoparticles embedded into pectin-allantoin-glycerol

matrix as promising UV photoprotective systems Marcela-Corina Rosu1, Lidia Magerusan2, Cristian Tudoran3

1Isotopic Physics and Technology, National Institute for Research and Development

of Isotopic and Molecular Technologies, Cluj-Napoca, Romania 2Physics of Nanostructured Systems, National Institute for Research and Development

of Isotopic and Molecular Technologies, Cluj-Napoca, Romania 3Molecular and Biomolecular Physics, National Institute for Research and

Development of Isotopic and Molecular Technologies, Cluj-Napoca, Romania

Ag-doped TiO2 nanoparticles show enhanced photocatalytic and

antimicrobial activities and they are involved in various UV photoprotection,

self-cleaning, biomedical, textile or water treatment applications [1]. Pectin is

a carbohydrate polymer with biodegradable and jellifying properties that is

often used as therapeutic and drug delivery agent [2]. Allantoin, a product of

purine metabolism, is a natural anti-irritant, soothing, skin protecting and

repairing agent by stimulating cell proliferation and rapid skin cells

regeneration [3]. Ag-doped TiO2 nanoparticles embedded into pectin-

allantoin-glycerin matrix were prepared as film-systems. The films were

characterized by mean of X-ray diffraction, FTIR and UV-VIS

spectrophotometry in order to determine the morpho-structural and optical

characteristics. XRD patterns revealed a crystalline/amorphous structure of

the film-systems and the FTIR analysis indicated the presence of inorganic

component into the polymer-based matrix. The optical transmissions of the

films are influenced by the amount of Ag-doped TiO2 nanoparticles and the

addition of silver doping. The results showed that the obtained films have

suitable physical characteristics for practical photoprotection applications.

The present study could provide a basis for further optimization of the

prepared materials as photoprotective systems with high efficiency.

[1] B. Yu, K.M. Leung, Q. Guo, W.M. Lau, J. Yang, Nanotechnology 22 (2011) 1-9.

[2] R.K. Mishra, A.K. Banthia, A.B.A. Majeed, Asian J Pharm Clin Res, 5 (2012) 1-7.

[3] M.Y. Lee, N.H. Lee, D. Jung, J.A. Lee, C.S. Seo, H. Lee, J.H. Ki

37

Ps8 Charge transport phenomena in molecular spin crossover

compounds Constantin Lefter1,2, Simon Tricard1, Haonan Peng1, Gabor Molnar1, Lionel

Salmon1, Philippe Demont3, Aurelian Rotaru2, Azzedine Bousseksou1 1LCC, CNRS, Toulouse, France

2Faculty of Electrical Engineering and Computer Science & Advanced Materials and

Nanotechnology Laboratory (AMNOL), Stefan cel Mare University, Suceava,

Romania 3LPP-CIRIMAT, CNRS, Toulouse, France

Spin-crossover (SCO) complexes of 3d4 – 3d7 transition metal ions are

paradigmatic examples of molecular materials showing bistability in

magnetic, optical and electrical properties. The high spin (HS) – low spin

(LS) transition can be triggered by various external stimuli, such as

temperature, light illumination, pressure or magnetic field. Another aspect of

great interest is the possibility of synthesizing these compounds in a variety

of shapes and sizes, ranging from large crystals, micro/nano rods to thin

films or patterned films. The versatility of these materials combined with the

wide range of operating temperatures makes them attractive for molecular

nanoelectronic and spintronic devices like molecular switches, sensor,

displays and data storage devices. [1-3].

In this work we focus on the [Fe(Htrz)2(trz)](BF4) (Htrz = 1H-1,2,4-triazole)

family.

Fig.1 SCO compound structure and thermal dependence of the real part of conductivity.

We investigate the possibility of organizing micro-rods between

interdigitated gold electrodes and their DC characterization. The most

38

important achievement of our work is that we managed, for the first time, to

switch the compound from HS state to LS state using an external electric

field. This opens new perspectives in using this class of materials in

nanoelectronic devices. Also we analyzed the effect of shape and metal

dilution on AC parameters like conductivity, permittivity and electrical

modulus, providing spectacular findings. By using spherical nanoparticles

and high aspect ratio micro-rods, we observed a shape anisotropy effect, and

by diluting the complex with Zn(II) ions we determined that the Fe(II) center

plays an essential role in the polaron hopping conduction mechanism.

[1] P. Guetlich, et al. , Beilstein Journal of Organic Chemistry, 2013, 9, 342-391.

[2] G. Molnar, et al. , Journal of Materials Chemistry C, 2014, 2, 1360-1366.

[3] A. Rotaru, et al., Advanced Materials, 2013, 25, 1745-1749.

39

Ps9 Effects produced by bismuth irradiation on high resistivity silicon Catalin Palade, Adrian Slav, Sorina Lazanu, Magdalena Lidia Ciurea

Laboratory of Nanoscale Condensed Matter Physics, National Institute of Materials

Physics, Magurele, Romania

In this work, the defects produced in Si single crystals of 8000 Ωcm

resistivity by irradiation with Bi6+ ions of 28 MeV kinetic energy having

fluence of 5x1011 ions/cm2 are investigated. By penetrating the Si crystal, the

Bi ions totally lose their energy mainly interacting with the lattice, and

generate primary defects, i.e. vacancy-interstitial pairs. These defects produce

complex point defects, some of them acting as traps, and Bi ions finally stop.

The stopped Bi ions produce a strain field into the Si host lattice as they are

bigger and heavier than Si atoms. We investigate the trapping phenomena

under the stress field by measuring and modeling the thermally stimulated

currents without bias. We charged the traps illuminating the samples with

monochromatic light of 1000, 800 and 400 nm wavelength at low temperature

and recorded the discharge currents during quasistatic heating. The trapped

carriers produce an internal electric field which is superposed on the electric

field which we modeled the strain. The detrapped carriers move under this

total electrical field. We resolved the discharge currents by modeling into

seven traps. All traps parameters were determined. We show that almost all

the trap parameters depend on the strain field.

40

Ps10 Nanostructured powders elaboration by spvd (solar physical vapor

deposition) Vasile Rizea1, Marioara Abrudeanu1, Corneliu Munteanu2, Adriana-Gabriela

Plaiasu 1, Gabriel Neacsu1, Bogdan Istrate2, Eduard Sebastian Barca1 1Engineering Science, Pitesti University, Faculty of Mechanics and Technology,

Pitesti, Romania 2Engineering Science, “Gheorghe Asachi” Technical University of Iasi, Faculty of

Mechanical Engineering, Iasi, Romania

In the recent years the demand for nanopowders are increased drastically

because of its wide range of applications. The nanotechnology offers

opportunities in creating new features and functions. Several methods are

available for the production of nanopowders production. The objective of this

paper is to offer an introduction to the fundamentals of nanotechnology and

nanopowder production using solar energy. Solar energy as a renewable

energy is one of the sources that remain to be exploited in the future. In order

to achieve the above-mentioned goals, literature research has been the starting

point. The basic principle involved in the production of nanopowders consists

in using a solar reactor to produce nanostructured powders under sun energy

starting from commercial micropowdres. The nanostructured powders are

collected on a nanostructured ceramic filter under air or inert gas pressure. All

the synthesized powders were characterized by XRD and SEM observation in

order to obtain information about crystallographic and morphology data

strictly in correspondence with solar flux and pressure in solar reactor.

41

Ps11 The influence of magnetic nanoparticles on the oxidative activity in

cellulolytic fungi Maria Andries, Lacramioara Oprica, Emilia Creanga

1 Faculty of Physics, Alexandru Ioan Cuza University, Iasi, Romania 2 Faculty of Biology, Alexandru Ioan Cuza University, Iasi, Romania

Magnetic nanoparticles (MNPs) have extensive applications in biomedicine

and biotechnology [1-3] which raise important environmental issues. Study

was carried out to assess oxidative activity induced by MNPs in fungi

microorganisms, suggesting the need to elucidate the molecular and cellular

bases of MNPs toxicity. We present the results of cellulolytic fungi response

to core/shell magnetic systems supplied in their culture medium. The enzymes

indicating oxidative stress level were assayed in fungi mycelium at seven and

fourteen days after inoculation. The increase of malondialdehyde (MDA)

level – the final product of lipid peroxidation was evidenced. Dose-response

for catalase activity was revealed between MNPs concentration and MNPS

concentration while no correlated variations have resulted for measurements

of peroxidase activity. We could conclude that the main toxic product was the

hydrogen peroxide, because of reactive oxygen species released following the

MNPs influence.

1. Prasa G L, Biomedical Applications of Nanoparticles, T.J. Webster (ed.), Safety of

Nanoparticles, Nanostructure Science and Technology -2009- P. 89-110.

42

Ps12 Stable colloidal suspension of magnetite nanoparticles for

applications in life sciences Emil Puscasu, Claudia Nadejde, Emilia Dorina Creanga

Faculty of Physics, ”Alexandru Ioan Cuza” University, Iasi, Romania

Various utilizations of magnetite nanoparticles, highly biocompatible, in

biomedicine and environmental sciences requires not only fine granulated

powder but also stable dispersion in aqueous media. Fe3O4 grains were

synthesized by chemical coprecipitation route using an adaptation of

Massart’s method [1]. The ferrophase was yield from ferric and ferrous iron

salts solutions mixed at relatively high temperature in alkali medium being

further stabilized in deionized water by coating with perchloric acid in order

to prevent the agglomeration and precipitation. Granularity of colloidal

magnetite was analyzed using SEM, crystalline properties were evidenced by

XRD while superparamagnetic characteristic, magnetic core size and

saturation magnetization by VSM investigation were assessed. The results are

similar to the literature, proving that magnetite nanoparticles coated with

perchloric acid obtained using our method could be useful in biological

applications or environment remediation.

[1]. Massart R., Preparation of aqueous magnetic liquids in alkaline and acidic media. IEEE

Transactions on Magnetics, Mag-17, 2, (1981) , pp. 1247-1248.

43

Ps13 The influence of Al2O3 and TiO2 deposited coatings to the behavior

of an aluminum alloy subjected to mechanical shock Geanina Laura Pintilei1, Marioara Abrudeanu1, Corneliu Munteanu2, Cristian

Petrescu1, Dorin Luca3, Vasile Ionut Crismaru2 1Engineering Science, Pitesti University, Faculty of Mechanics and Technology,

Pitesti, Romania 2Engineering Science, “Gheorghe Asachi” Technical University of Iasi, Faculty of

Mechanical Engineering, Iasi, Romania 3Department of technologies and equipments for materials processing, “Gheorghe

Asachi” Technical University of Iasi, Faculty of Materials Science and Engineering ,

Iasi, Romania

Aluminum alloys are used in the aerospace industry due to their good

mechanical properties and their low density compared with the one of steels.

Usually the parts made of aluminum alloys contribute to the structural frame

of aircrafts and they must withstand static and variable mechanical loads and

also mechanical loads applied in a very short time which determine different

phenomenon’s in the material behavior then static or fatigue loads. This paper

analysis the resilience of a 7075 aluminum alloy subjected to shock loads and

the way how a coating can improve its behavior. For improving the behavior

two coatings were considered: Al2O3 with 99.5% purity and TiO2. The

coatings were deposited on the base material by plasma spraying and

electrochemical deposition. The samples with and without coating were

subject to mechanical shock to determine the resilience of the materials and

the cracks propagation was investigated using SEM analysis. To highlight the

physical phenomenon’s that appear in the samples during the mechanical

shock, explicit finite element analysis were done using Ansys 14.5 software.

44

Ps14 The preparation and the characterization of some water-based

ferrofluids Gabriel Oanca1, Claudia Nadejde1, Florin Brinza1, Laura Ursu2

1Faculty of Physics, “Alexandru Ioan Cuza” University, Iasi, Romania 2Instrumental Analyses and Scientific Imaging Department, “Petru Poni”

Macromolecular Chemistry Institute, Iasi, Romania

Magnetite and oleic acid are known as developing the strongest core-shell

interactions so that the resulted colloidal systems are the most stable in liquid

suspensions. Sodium oleate is the best hydro soluble substitute of oleic acid

being also known for its biocompatibility [1]. We have prepared water-based

ferrofluids with magnetite/sodium oleate as ferrophase in two different

variants (basic and acidic) of classical method of ferric and ferrous ions

coprecipitation. Comparative analysis of the two ferrofluids was

accomplished by applying NTA (nanoparticle tracking analysis) and DLS

(dynamic light scattering), while ferrophase crystallinity was investigated by

XRD (X-ray diffraction). NTA and DLS results revealed relatively narrow

size distributions of the nanoparticles with hydrodynamic diameters no higher

than 110 nm. Also, from NTA recordings, the concentration of the magnetic

nanoparticles in both samples was determined (around 1013 particles/ml). The

XRD data confirmed the presence of magnetite crystallites with typical spinel

structure in both samples and allowed crystallites size estimation. According

to DLS measurements, high Zeta potential was found for both colloidal

suspensions: -61.04 mV for the first sample, prepared in basic medium, and -

64.97 mV for the second sample synthesized in acidic conditions; the

obtained values confirmed the good stability of both ferrofluids against

dipole-dipole attraction forces. Moreover, it was found that the second sample

exhibits a lower polydispersity index (0.655) than the first one (0.974). Real

time tracking of ferrophase grains by NTA evidenced however rare

aggregates of colloidal particles for both variants of preparation protocol. The

next stage of our research work will be focused on such aggregates frequency

limitation by improved monitoring of secondary reaction products

accompanying ferrophase yielding.

[1] Sun J., Zhou S., Hou P., Yang Y., Weng J., Li X., Li M., Synthesis and characterization of

biocompatible Fe3O4 nanoparticles, Journal of Biomedical Materials Research Part A, 80(2),

(2007), pp. 333-341.

45

Ps15 10 mol% YSZ ceramics and composites synthesis, characterization

and electric properties Vasile-Adrian Surdu1, Bogdan Ştefan Vasile1, Ecaterina Andronescu1,

Cristina Daniela Ghiţulică1, Roxana Trşucă2, Cristian Hornoiu3 1Department of Science and Engineering of Oxide Materials and Nanomaterials,

University Politehnica of Bucharest, Bucharest, Romania 2METAV R and D, Bucharest, Romania

3"Ilie Murgulescu" Institute of Physical Chemistry, Bucharest, Romania

Fully yttria stabilized zirconia is one of the most attractive zirconia based

ceramics for various applications and it is used in various fields, especially as

electrolyte for SOFCs, due to its good chemical and electrical properties. The

aim of the present study was to investigate the influence of the synthesis route

and sintering method of 10 mol% YSZ ceramic and 10 mol%YSZ with 5 wt%

Al2O3 composites and to determine the effect of Al2O3 addition on its electric

properties.

10 mol% YSZ and YSZ – 5wt% Al2O3 composite nanopowders were

prepared through modified-Pechini method. The composites were prepared by

two routes: the first one involves in situ synthesis of and the second one was

carried out by adding the obtained YSZ powder in the alumina precursor

solution. The obtained powders were densified using classic and spark plasma

sintering methods.

The nanopowders and ceramics were characterized using X-Ray diffraction,

Scanning Electron Microscopy, High Resolution Transmission Electron

Microscopy and Impedance Spectroscopy at high temperature. The measured

total conductivity shows that the addition of Al2O3 with SPS sintering

technique induces a higher conductivity.

46

Ps16 Electromagnetic investigation of carbon fiber reinforced plastics Rozina Steigmann1,2, Adriana Savin1, Felicia Iacomi2

1Nondestructive Testing, National Institute of Research and Development for

Technical Physics, Iasi, Romania 2Faculty of Physics, Alexandru Ioan Cuza University, Iasi, Romania

Carbon Fiber Reinforced Plastics (CFRP) are multilayered composite

materials with applications among most different from aeronautic industry to

sport goods. The principals factors that recommend the use of CFRP are low

density, high elastic modulus along the carbon fibers direction, high ultimate

strength along the same direction, did not present fatigue phenomena and the

expansion coefficient is small. The disadvantages of these materials are low

strength at impact even at low energies (1-10J) that can lead to delaminations

with and without fiber breaking, matrix deterioration due to chemical action

of adsorbed water, the impossibility to use it at temperature over glass

transition temperature [1]. CFRP is a paramagnetic composite (μ_r=1), having

electrical conductivity relatively high in the fibers plan, 102-104 S/m [2]. Plate

from CFRP laminas with thickness of 1.91 mm, made from

Polyphenylenesulphide (PPS) reinforced with carbon fibers. The plates were

impacted with energies between 1J and 10J with an impactor with semi-

spherical bumper head with 22.5mm mm diameter. For the detection of

delaminations, a send –receiver transducer was used, the reception coil being

concentric with the emission one and was diaphragmed with a circular

aperture having the diameter of hole 0.25mm. The transducer is connected to

the 4395A- Agilent USA. The transducer scans a surface of 60x60mm^2 with

0.25mm steps on both directions. The scanning is assured by an X-Y

motorized stage Newmark USA. The command of 4395A is made through

IEEE488.2 Keitley interface and the displacing system through RS 232

interface by means of a program developed in Matlab 2011ba. The data

delivered by the transducer are stored as amplitude and phase information.

The presence of circular aperture and the extremely small lift-off (0.1mm)

allow that the post-processing of the obtained signals shall be made using

Fourier optics methods [3].

This work was supported by the strategic grant POSDRU/159/1.5/S/137750, Project

“Doctoral and Postdoctoral programs support for increased competitiveness in Exact Sciences

research” cofinanced by the European Social Found within the Sectorial Operational Program

Human Resources Development 2007 – 2013

1. P. Morgan, Carbon fibers and their composite, CRC Press, Taylor & Francis, Boca Raton, 2005.

2. R. Grimberg, SC. Wooh, A. Savin, R. Steigmann, D. Premel, INSIGHT, 44, (5), pp.289-293, 2002.

3. M. Born, Principles of Optics, 1959.

47

Ps17 Investigation of composites based on Poly–ε–caprolactone and

magnetic/ferroelectric nanoparticles Vlad Preutu, Roxana Stanculescu, Mirela Airimioaei, Liliana Mitoseriu

Physics Department, Alexandru Ioan Cuza University of Iasi, Iasi, Romania

Poly–ε–caprolactone (PCL) is a biocompatible, biodegradable and

bioresorbable polymer with many interesting physicochemical properties:

drug permeability, non-toxicity, slow degradation, and low melting point.

Thus PCL may have medical applications, such as medical devices, drug

delivery and tissue engineering [1].

According to the literature, the PCL/ferrites composites can be employed in

bioengineering and medical fields: nanoparticle as magnetite encapsulated in

PCL microcapsules could be used for bone replacement or as shape–memory

composites in biomedicine, while the CoFe2O4/PCL core–shell has a great

potential for magnetic fluid hyperthermia in cancer treatment [2].

In this work, the investigation of properties of PCL–based composites filled

with magnetic (CoFe2O4) or ferroelectric (BaTiO3) nanoparticles are reported.

The composites formation and their characteristic as structure and

microstructure were investigated by XRD and SEM analyses. For all the

samples, the frequency dependence of dielectric properties at room

temperature have been investigated and discussed in correlation with the

microstructural data.

The magnetic properties of PCL/CoFe2O4 composites determined with a

vibrating sample magnetometer (VSM) show a reduction of magnetization

when decreasing the ferrite amount.

Acknowledgements: The support of PNII-PT-PCCA-2013-4-1119 MECOMAP

grant is acknowledged.

[1] M. A. Woodruff, D.W. Hutmacher, Progress in Polymer Science 35 (2010) 1217–1256.

[2] X. Yu, S. Zhou, X. Zheng, T. Guo, Y. Xiao, B. Song, Nanotechnology, 20 (2009) 235702.

48

Ps18 Morphological changes in metallic core/polymer shell

nanostructures at the interaction with physiological media Daniela - Angelica Pricop1, Lucian Hritcu2, Carmen - Mariana Popescu1

1Physics Department, "Alexandru Ioan Cuza" University, Iasi, Romania 2Biology Department, "Alexandru Ioan Cuza" University, Iasi, Romania

Gold nanoparticles were synthesized in high molecular weight chitosan

matrix by co-precipitation chemical route. Previous in vivo studies reported

no morphological changes occurred in rats brain tissue after administration

of such capped gold nanoparticles. In this paper we focused on size

distribution analysis of nanoparticles in the areas where they were localized

in comparison to their dimensional distribution in colloidal suspension.

Microscopy investigation in dark field technique revealed that nanoparticles

from brain tissue appeared to have changed size.

Fig.1 GNPs in rats brain

To understand the factors that caused the decrease of nanoparticles

dimensions, we proceed to the simulation of physiological conditions i.e.

basic pH environments similar to that of hydrocephalus medium. The main

result evidenced that extremely basic medium significantly modified the

polymer coating and its configuration around the metallic core.

1.Sathish kumar K., Madhusudhanan J., Thanigaivel, Robin A., Veni V. Biofunctionalized

nanoparticle for drug delivery,Research Journal of Biotechnology, 2013,8,70-77.

49

Ps19 Structural and magnetic properties of superparamagnetic

magnetite nanoparticles superficially isolated with biocompatible

polymers Gigel Gicu Nedelcu1, Mihail Liviu Craus2, Felicia Iacomi1

1Physics Department, "Alexandru Ioan Cuza" University, Iasi, Romania 2Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia

Magnetite nanoparticles superficially isolated with polymers have been

synthesized by co-precipitation method using ferrous and ferric salts, with the

addition of an alkaline solution of NaOH and three polymer solutions of

polyethylene glycol, polyvinyl alcohol or a polysaccharide, such as dextran.

The scanning electron microscopy and X-ray diffractometry measurement

show that particle size are in the range of 10-12 nm and have a spherical

shape.

The hysteresis cycles of bare magnetite nanoparticles (a) and for those coated with dextran (b),

polyethylene glycol (c) and polyvinyl alcohol (d).

Vibrating sample magnetometry analysis has provided details on

superparamagnetic behavior of the magnetite nanoparticles. The study about

interaction between individually coated magnetite nanoparticles offer clues on

fact that nanoparticles are not agglomerates.

[1] R. Sharma, A. Sharma, C.J. Chen, Open Nanomed. J. 3 (2011) 10-23.

[2]S. Laurent, S. Dutz, U.O. Häfeli, M. Mahmoudi, Adv. Coll. Int. Sci. 166 (2011) 8–23.

50

Ps20 The inorganic oxide network microstructure in Si based ormosils

prepared by gamma radiation Joana Lancastre1, António Falcão1, Fernanda Margaça1, Luís Ferreira1, Isabel

Miranda Salvado2, M. Helena Casimiro3, Álmásy Laszlo4, Anikó Meiszterics5 1C2TN, Instituto Superior Técnico, Universidade de Lisboa , Bobadela, LRS,

Portugal 2CICECO & Departamento de Engenharia de Materiais e Cerâmica, Universidade de

Aveiro, Aveiro, Portugal 3REQUIMTE/CQFB, Departamento de Química, Faculdade de Ciências e

Tecnologia, FCT, Universidade Nova de Lisboa, Caparica, Portugal 4Wigner Research Centre for Physics, Institute for Solid State Physics and Optics,

Budapest, Hungary 5Gedeon Richter LTD, Gedeon Richter LTD, Budapest, Hungary

Ormosils are organic-inorganic materials that have been the object of

intense research due to their wide range of properties and inumerous

applications. We have prepared hybrid materials of this type by gamma

irradiation of mixtures of the precursors, tetraethyl orthosilicate,

polydimethylsiloxane silanol terminated and zirconium propoxide, without

addition of any other component. Several variables have been found to

influence the microstructure of the final material. This work presents the

effect of the two parameters that were found to be the most relevant. A batch

of samples was prepared varying the polymer molecular weight while keeping

the same wt% composition of all precursors. Another batch of samples was

produced with fixed molecular weight and polymer content but changing the

Zr propoxide content. All samples were dried in air at room temperature and

then characterized by Small Angle Neutron Scattering and Scanning Electron

Microscopy among other techniques. The results shed light on the

development of the inorganic oxide network from a preparation mixture

devoid of water and on the role played by those determinant variables. A

model is proposed for the microstructure of the materials so prepared.

51

Ps21 Synthesis of nanomaterials with potential application in sensitized

solar cell Daniel Florin Sava, Anton Ficai, Bogdan Stefan Vasile, Georgeta Voicu, Ecaterina

Andronescu

Science and Engineering of Oxide Materials and Nanomaterials, Politehnica

University of Bucharest, Faculty of Applied Chemistry and Material Science,

Bucharest, Romania

Nanostructured semiconductors have a lot of applications in different

fields from electronics to medicine. One important application of these

materials is sensitized solar cells, which “threaten” to become the best solar

cell type regarding the W/$ ratio. Sensitized semiconductors became of

interest for many scientists only from 1972 but they really took scale in 1991

when Gratzel et al. thought of using nanostructured semiconductors for

constructing the solar cells and the efficiency made a big jump to 8%. [1] This

type of solar cells have known another big step in 2006 when Kojima et al.

used a hybrid perovskite structure as a sensitizer for the solar cell.[2]

Currently the highest efficiency for sensitized solar cells is 19,3% obtained

with the hybrid perovskite structure.[3] We present in this work the synthesis

of two important nanomaterials that could be used together as a composite in

constructing a low cost dye sensitized solar cell, specifically the photoanode.

The synthesized materials are the anatase form of TiO2 with a cubic

morphology that it is done through a simple hydrothermal method while and

graphene oxide which is synthesized through a modified Hummer method.

Graphene oxide could also be used to replace the counterelectrode in the solar

cell, but both materials have the purpose of increasing the charge transport

inside the photoanode. The obtained materials were characterized through

several methods: XRD, SEM, TEM, IR spectroscopy and BET

adsorption/desorption isotherms. From the results we see the importance of

controlling very well the synthesis parameters and their effect on the

properties of the obtained materials.

1. Oregan, B., M. Gratzelș; Nature, 1991. 353(6346): p. 737-740.

2. Kojima, A., Teshima, K., Shirai, Y., Miyasaka, T., in 210th ECS Meeting2006: Cancun,

Mexico.

3. Service, R.F., Science, 2014, 344(6183): p. 458.

52

Ps22 Magnetoresistance behavior in thermally treated organic spin

valve Aurelian Carlescu1, Felicia Iacomi1, Christian Bernhard2

1Physics Faculty, "Alexandru Ioan Cuza" University of Iasi, Iasi, Romania 2Physics Department, University of Fribourg, Fribourg, Switzerland

Organic Spintronics has been considered to be the physics and

applications of spin polarized electron injection, transport, manipulation and

detection in organic diodes by the application of an external magnetic field.

We build an organic spin-valve (OSV), which is based on an organic

semiconductor spacer placed in between two ferromagnetic electrodes having

different coercive fields, of which magnetoresistance changes with the applied

field. Epitaxial La0.875MnO3Sr0.125 (LSMO) thin films were grown by

pulsed laser deposition; the organic spacer Alq3 and the top ferromagnetic

electrode Co were deposited using thermal evaporation method in vacuum.

The films thickness was determined with X-ray reflectrometry (XRR) and the

simulations of the XRR data have been performed using the software package

GenX. Magnetoresistance measurements were performed using the four-point

probe option of a physical properties measurement system (PPMS) from

Quantum Design (Model QD6000). This device was heated in vacuum to

various annealing temperatures starting from 423 K to 453 K in steps of 10 K

and for a duration of 12 hours each, in order to observe the evolution of the

magneteresistance. Key-words: valve spin, spintronics, organic

semiconductor, magnetoresistance, thermal deposition.

53

Ps23 The model for laser annealing of non-linear crystals Anton Smirnov1, Nikita Bityurin

Laboratory of laser nanomodification of materials , Institute of Applied Physics of the

Russian Academy of Sciences, Nizhny Novgorod, Russia

The applicability of high-power laser pulses is limited by the stability of

the optical element. For the nanosecond pulses the threshold of the optical

damage of the transparent non-linear crystals used for laser frequency

conversion is determines by the laser heating of light-absorbing inclusions.

One of the methods of improving crystal’s quality is the sub-threshold

laser annealing. To our knowledge the mechanisms of this process have not

been properly understood. We suggest a simple model that concerns diffusion

mechanism of the laser annealing. Laser heating of the cluster of the

absorbing defects leads to activation of the diffusion of the defects decreasing

thereby their number density. Since the temperature rise is proportional to

absorbing centers concentration, the threshold of destruction becomes higher.

In order to develop this idea we have formulated theoretical problem. It is

based on the diffusion equation for the number density of the absorbing

centers with temperature dependent diffusion coefficient, and the heat

diffusion equation for the temperature distribution within the sample. The

dynamics of the defect’s concentration during the annealing is investigated

analytically thus allowing us to follow the dependence of laser damage

threshold on the fluence of annealing pulses, their number, and the

temperature of the thermostat.

54

Ps24 Photocatalytic evaluation of ferrite nanoparticles synthesized in

palm oil Constantin Virlan, Daniel Gherca, Aurel Pui

Faculty of Chemistry, "Alexandru Ioan Cuza" University, Iasi, Romania

The aim of the present study is to evaluate the photocatalytic activity of

magnetic ferrites, MFe2O4 (M= Mg, Mn, Co, Ni, Cu, Zn) synthesized through

coprecipitation using palm oil as capping agent and surfactant. The

nanoparticles have been synthesised using the coprecipitation method but

using Palm Oil as surfactant and capping agent, a cheap, easy accessible, non-

toxic reagent, this feature representing the innovation factor of the synthesis.

Fig. 1 XRD spectrum of as synthesized MgFe2O4

The as-prepared nanoparticles were characterized by X-ray diffraction

(Figure 1), UV-Vis and FT-IR spectroscopy, SEM imaging as well as

regarding the magnetic properties and surface characterization using BET.

The photocatalytic activity was evaluated on the degradation of various dyes

in the presence of visible light without adding any oxidizing agents. The

photocatalytic activity was evaluated regarding the influence of the divalent

metal in the ferrites. The ferrites as synthesized represent a class of materials

with possible environmental applications due to the ease of separation using a

magnetic field and the fact that they use visible light, much more abundant in

the solar spectrum compared to TiO2 and derivatives that use ultraviolet light.

[1] Erik Casbeer , Virender K. Sharma, Xiang-Zhong Li. Synthesis and photocatalytic

activity of ferrites under visible light: A review, Separation and Purification

Technology, Volume 87, 2012, pages 1–14.

55

Ps25 Structural investigation of surface and biological properties of

some composite resins for dental reconstruction Diana Diaconu1, Odette Luca1, Stefan Ionita2, Daniel Timpu3, Felicia Iacomi2,

1Dental Medicine Faculty, Gr.T.Popa University of Medicine, Iasi, Romania 2Faculty of Physics, Alexandru Ioan Cuza University of Iasi, Iasi, Romania

3Petru Poni Institute for Macromolecular Chemistry, Iasi, Romania

Nanotechnology induced in dentistry many dental treatment procedures

fast, reliable, safe, and much less painful. Resin composite materials are

popular due to their aesthetic appearance and wear properties designed to

replicate the properties of enamel. The appearance of a dental restoration is a

combination of events of surface reflection, absorption, and internal

scattering. Enamel naturally displays a high degree of translucency and this is

why the translucency is a desirable characteristic for restorative materials. In

this paper we discuss some surface and biological properties of a biological

structure in comparison with different photopolymerizable composite resins

for dental reconstruction and correlate them with the structural investigation.

56

Ps26 Structural investigation of Ni- and Co-doped ZnO thin films grown

by spin coating Mihaela Toma, Luciana Punga, Denisa Mihu, Cipriana Padurariu, Vlad

Ifrosie, Stefan Irimiciuc, Marius Dobromir, Valentin Nica, Felicia Iacomi Faculty of Physics, Alexandru Ioan Cuza University of Iasi, Iasi, Romania

Nanocrystalline thin films of low Ni and Co-doped ZnO were deposited

onto glass and quartz substrate by using a spin coating method. Structural,

optical and magnetic properties were investigated by using, X-ray diffraction

(XRD), X-ray photoelectron spectroscopy (XPS) and electron paramagnetic

spectroscopy (EPR). At low doping level, local structure remains identical to

ZnO with subtle increase in the bond length. XPS and the optical absorption

measurements indicate valence +2 both for Ni and Co. Undoped as well as

doped ZnO thin films are weakly ferromagnetic proving that ferromagnetic

ordering in thin films is primarily a manifestation of point defects and

incorporation of transition metal impurities plays a secondary role.