Research Highlights
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Research Highlights Donna C. Arnold Functional Materials Group, School of Physical Sciences, University of Kent, Canterbury, Kent, CT2 7NZ, UK Magnetic Nanomaterals B-site Doping CMP processing Before Acknowledgement s CaMn 2 O 4 Nanowires Magnetic nanowires often exhibit different properties to the bulk and are potentially useful for magnetic device application. CaMn 2 O 4 nanowires exhibit ferromagnetic ordering in contrast to the antiferromagnetic bulk. Ferromagnetism arises as a result of uncompensated surface spins. -10 -5 0 5 10 -2 10 4 0 2 10 4 T=2 K T=25 K T=300 K M (em u/g) H (O e) -10 -5 0 5 10 -20000 0 20000 M (em u/g) H (O e) a b c Co/Fe 3 O 4 Core/Shell Nanocables Co/Fe 3 O 4 core/shell nanocables (and vice versa) can be synthesised within the pores of AAO membranes by supercritical fluid inclusion methods. The magnetic properties can be ‘tuned’ by varying the core:shell ratio. 100 nm 3 nm 100 nm 3 nm Co Co Co Co Fe 3 O 4 Fe 3 O 4 Fe 3 O 4 Fe 3 O 4 -1000 -500 0 500 1000 -10000 -5000 0 5000 10000 Co -Fe 3 O 4 nanocables Fe 3 O 4 -C o nanocables M (kA/m ) B (O e) T=300 K -2000 -1000 0 1000 2000 -10000 -5000 0 5000 10000 Co -Fe 3 O 4 nanocables Fe 3 O 4 -C o nanocables M (kA/m ) B (O e) T=1.8 K Ge/SiO x Core/Shell Nanocables and DMS Nanowires Ge/SiO x core/shell nanocables can be synthesised from single source precursors. Small amounts of Mn can be incorporated yielding room temperature ferromagnetism . C. Arnold et al, Chem. Phys. Chem., 2007, 8(11), 1694 B. Daly, D. C. Arnold et al, Small, 2006, 2(11), 1299 . C. Arnold et al, J. Mater. Chem., 2009, 19, 954 . Kazakova, J. S. Kulkarni, D. C. Arnold et al, J. Appl. Phys., 2007, 101(9), 09H108 . L. Rice, D. C. Arnold et al, Adv. Funct. Mater., 2007, 17(1), 133 . C. Arnold et al, Appl. Surf. Sci., 2009, 255(23), 9333 . C. Arnold et al, IEEE Trans. Nanotech., 2010, In press D. C. Arnold et al, Phys. Rev. Lett., 2009, 102, 027602 . C. Arnold et al, Adv. Funct. Mater., 2010, 20(13), 2116 D. C. Arnold et al, J. Mater. Chem., 2009, 36, 6485 University College Cork University of St Andrews ISIS neutron facility ILL neutron facility European Synchrotron radiation Facility (ESRF) Diamond Light Source
description
Fe 3 O 4. Co. Fe 3 O 4. Co. 100 nm. Fe 3 O 4. Co. 100 nm. Fe 3 O 4. Co. 3 nm. 3 nm. Research Highlights. Donna C. Arnold. Functional Materials Group, School of Physical Sciences, University of Kent, Canterbury, Kent, CT2 7NZ, UK. Magnetic Nanomaterals. - PowerPoint PPT Presentation
Transcript of Research Highlights
Research Highlights Donna C. Arnold
Functional Materials Group, School of Physical Sciences, University of Kent, Canterbury, Kent, CT2 7NZ, UK
Magnetic Nanomaterals
B-site Doping
CMP processing
Before
Acknowledgements
CaMn2O4 Nanowires
Magnetic nanowires often exhibit different properties to the bulk and are potentially useful for magnetic device application.
CaMn2O4 nanowires exhibit ferromagnetic ordering in contrast to the antiferromagnetic bulk. Ferromagnetism arises as a result of uncompensated surface spins.
-10
-5
0
5
10
-2 104 0 2 104
T=2 KT=25 KT=300 K
M(e
mu
/g)
H (Oe)
-10
-5
0
5
10
-20000 0 20000
M(e
mu
/g)
H (Oe)
a
b
c
Co/Fe3O4 Core/Shell Nanocables
Co/Fe3O4 core/shell nanocables (and vice versa) can be synthesised within the pores of AAO membranes by supercritical fluid inclusion methods. The magnetic properties can be ‘tuned’ by varying the core:shell ratio.
100 nm
3 nm
100 nm
3 nm
Co
Co
Co
Co
Fe3O4
Fe3O
4
Fe3O4
Fe3O4
-1000
-500
0
500
1000
-10000 -5000 0 5000 10000
Co - Fe3O
4 nanocables
Fe3O
4 - Co nanocables
M (
kA/m
)
B (Oe)
T=300 K
-2000
-1000
0
1000
2000
-10000 -5000 0 5000 10000
Co - Fe3O
4 nanocables
Fe3O
4 - Co nanocables
M (
kA/m
)
B (Oe)
T=1.8 K
Ge/SiOx Core/Shell Nanocables and DMS Nanowires
Ge/SiOx core/shell nanocables can be synthesised from single source precursors. Small amounts of Mn can be incorporated yielding room temperature ferromagnetism
D. C. Arnold et al, Chem. Phys. Chem., 2007, 8(11), 1694 B. Daly, D. C. Arnold et al, Small, 2006, 2(11), 1299D. C. Arnold et al, J. Mater. Chem., 2009, 19, 954O. Kazakova, J. S. Kulkarni, D. C. Arnold et al, J. Appl. Phys., 2007, 101(9), 09H108R. L. Rice, D. C. Arnold et al, Adv. Funct. Mater., 2007, 17(1), 133D. C. Arnold et al, Appl. Surf. Sci., 2009, 255(23), 9333D. C. Arnold et al, IEEE Trans. Nanotech., 2010, In press D. C. Arnold et al, Phys. Rev. Lett., 2009, 102, 027602D. C. Arnold et al, Adv. Funct. Mater., 2010, 20(13), 2116 D. C. Arnold et al, J. Mater. Chem., 2009, 36, 6485
University College CorkUniversity of St AndrewsISIS neutron facilityILL neutron facilityEuropean Synchrotron radiation Facility (ESRF)Diamond Light Source
