A

B

FIGURE 1.3 Examples of homotops in small nanoalloys: (A) complete inversion of configura-

tion in a fivefold symmetric 38-atom A19B19 NA; (B) high symmetry homotops for a 38-atom

A6B32 truncated octahedral NA.

Fullerenes Ionic NPsMolecular NPs

Metal NPs Passivated MNPs Nanoalloys

FIGURE 1.1 Examples of types of nanoparticles. The image of the passivated metal nanoparti-

cle (middle of bottom row) is taken from Walter M, Akola J, Lopez-Acevedo O, Jadzinsky PD,

Calero G, Ackerson CJ. Proc Natl Acad Sci USA 2008;105:9157. Copyright 2008 National

Academy of Sciences, USA.

Segregated Mixed

Core–Shell

A

B

D

C

Onion-like

Layered

Ordered

Random

FIGURE 1.4 Types of chemical ordering observed for nanoalloys. Reprinted with permission

from Ferrando R, Jellinek J, Johnston RL. Chem Rev 2008;108:845. Copyright 2008 American

Chemical Society.

3 nm 5 nm

5 nm50 nm

FIGURE 1.5 HRTEM and energy-filtered TEM (bottom left) images of Cu–Ag NAs. Langlois C,

Alloyeau D, Le Bouar Y, Loiseau A, Oikawa T, Mottet C. Faraday Disc 2008;138:375. Reproduced

by permission of the Royal Society of Chemistry. [For the electronic version: http://dx.doi.org/

10.1039/b705912b].

60 100 140 180 220

Frequency (cm–1)

Au20Kr

Au19Kr

Au20

Au19

Au19

Au20

4

2

9

6

3

0

s(n

)s

(n)

IR a

bsor

ptio

n co

-eff

icie

nt /

km m

ol-1

A

B

C

D

FIGURE 1.6 IR photodepletion spectra of (Au19)Kr (A) and (Au20)Kr (B) and the calculated

vibrational spectra of Td-symmetry Au20 (C) and C3v-symmetry Au19 (D). The proposed struc-

tures are shown on the right. From Gruene P, Rayner DM, Redlich B, van der Meer AFG,

Lyon JT, Meijer G. Science 2008;321:674. Reprinted with permission from AAAS.

Icosahedron Ino-decahedron Cuboctahedron (fcc)

FIGURE 1.9 Five-shell (561-atom) geometric shell NPs.

Δ 34(

DF

T)

/ eV

fivefold pIh sixfold pIh

TO

pIh

Dh-cp(T)

Marks Dh

Dh-cp(DT)

A

B

Dh-cp(T)

Dh-cp(DT)

0.0

–0.5

–1.0

–1.5

–2.0

–2.5

17 18

1.118 ev

0.427 ev0.401 ev0.285 ev0.271 ev0.115 ev

0.0 ev a

Gupta DFT

bcdef

g

a

b

0.6911 eV0.7537 eV

1.2571 eV

1.5619 eV

1.9484 eV2.0599 eV

0.0 eV

cd

e

f

g

19 20 21 22 23

m

24 25 26 27 28

FIGURE 1.10 Results from a hybrid EP–DFT study of 34-atom Pd–Pt NAs. (A) Comparison of

the DFT mixing energies (D34(DFT)) as a function of the number of Pd atoms (m). The dotted line

connects structures corresponding to the lowest energy isomers found for the Gupta potential. The

solid line connects Dh-cp(DT) isomers which are found to be the DFT GM across this composi-

tion range. Reprinted with permission from Paz-Borbon LO, Johnston RL, Barcaro G,

Fortunelli AJ. Phys Chem C 2007;111:2936. Copyright 2007 American Chemical Society. (B)

Change in relative stability of structural motifs for Pd24Pt10 on going from the empirical (Gupta)

potential to DFT level. Pd atoms are shown in dark grey and Pt in light grey. Ferrando R,

Fortunelli A, Johnston RL. Phys Chem Chem Phys 2008;10:640—Reproduced by permission of

the PCCP Owner Societies. [For the electronic version: http://dx.doi.org/10.1039/b709000e].

Ag27Cu7 Au34Cu6 Ag27Cu13 Ag32Ni13

FIGURE 1.11 Examples of the four most stable core–shell polyicosahedra. Each cluster is

shown from two different perspectives. (From left to right) Fivefold pancake of size 34, capped

sixfold pancake of size 40, capped fivefold pancake of size 40 and anti-Mackay icosahedron of

size 45. Reprinted with permission from Ferrando R, Jellinek J, Johnston RL. Chem Rev

2008;108:845. Copyright 2008 American Chemical Society.

400

0

0.2

T (K)

LRO

0.4

0.6

0.8

1

600 800 1000

T < Tc T > Tc

A

B

2 nm 2 nm

(i) (ii)

FIGURE 1.12 (A) Simulation of the order–disorder transition in 3 nm CoPt nanoalloys.

Reprinted figure with permission from Andreazza P, Mottet C, Andreazza-Vignolle C, Penuelas

J, Tolentino HCN, De Santis M. Phys. Rev. B 2010;82:155453. Copyright 2010 by the American

Physical Society. (B) HRTEM images (and inset electron diffraction patterns) of CoPt nanoparti-

cles with (i) ordered (L10) and (ii) disordered structures. Adapted by permission from Macmillan

Publishers Ltd: Nature Materials (Alloyeau D, Ricolleau C, Mottet C, Oikawa T, Langlois C,

Le Bouar Y. Nat Mater 2009;8:940), Copyright 2009.

For part (A): Readers may view, browse, and/or download material for temporary copying pur-

poses only, provided these uses are for noncommercial personal purposes. Except as provided

by law, this material may not be further reproduced, distributed, transmitted, modified, adapted,

performed, displayed, published, or sold in whole or part, without prior written permission from

the American Physical Society. [http://link.aps.org/abstract/PRB/v82/e155453]. For part (B): In

electronic form, http://www.nature.com/nmat/.

0 0.14.0

5.0

6.0

7.0

8.0

9.0

10.0

0.2 0.3 0.4 0.5

IP[eV]

1/R[Å]

6s

6p

AtomInsulatingvan der Waalsclusters

Metallic clustersand bulk metal

E F

Ws

Wp

dspdsp > kBT

dsp ≈ 0

A

B

FIGURE 1.14 (A) Variation of ionization energies of mercury NPs with radius, compared with

the prediction of the Liquid Drop Model (dashed line). Reprinted figure with permission from

Rademann K, Kaiser B, Even U, Hensel F. Phys Rev Lett 1987;59:2319. Copyright 1987 by the

American Physical Society. (B) The evolution of band structure with increasing size of mercury

NPs. Reprinted (Figure 5.8, p. 138) from Johnston RL. Atomic and Molecular Clusters. London:Taylor and Francis; 2002.

For part (A): Readers may view, browse, and/or download material for temporary copying pur-

poses only, provided these uses are for noncommercial personal purposes. Except as provided

by law, this material may not be further reproduced, distributed, transmitted, modified, adapted,

performed, displayed, published, or sold in whole or part, without prior written permission from

the American Physical Society. [http://link.aps.org/abstract/PRL/v59/p2319].