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Mater Sci Nanotechnol 2017 | Volume 1 Issue 2
allied
academies
Nanomaterials and Nanochemistry
November 29-30, 2017 | Atlanta, USA
International Conference on
ε
-Fe
2
O
3
nanomagnet, one of the four polymorphs of iron
oxide Fe
2
O
3
, was first discovered by our group as a pure
phase via a chemical nanoparticle synthesis, a combination
of reverse-micelle and sol-gel methods. This material exhibits
a large coercive field over 20 kOe at room temperature and
the magnetic properties could be widely controlled by metal
substitution. In this work, we report the theoretical calculations
of the electronic structure and phonon modes of ε-Fe
2
O
3
.
Using the crystal structure determined by powder X-ray
diffraction, we calculated the electronic structure of ε-Fe
2
O
3
using first-principles calculations and molecular orbital
calculations, and the origin of the huge coercive field was
investigated. Furthermore, we calculated the phonon modes of
ε-Fe
2
O
3
using the Phonon code. The lowest vibration mode was
calculated to be 2.51 THz due to the Fe atomvibration along the
crystallographic a-axis with A1 symmetry. The phonon modes
were experimentally observed by Far-IR spectroscopy, which
showed good agreement with the calculation results. Phonon
modes of metal-substituted ε-Fe
2
O
3
are also introduced.
Speaker Biography
Marie Yoshikiyo received her
M.Scin Chemistry from the University of Tokyo in 2013,
and pursuing her Ph.D under the supervision of Prof. Shin Ichi Ohkoshi. She is currently
a Project Assistant Professor of Department of Chemistry, School of Science at the
University of Tokyo. Her research interests focuses on the development of functional
materials, especially magnetic nanomaterials based on iron oxides.
e:
m-yoshikiyo@chem.s.u-tokyo.ac.jpMarie Yoshikiyo
The University of Tokyo, Japan
Theoretical calculations of the electronic structure and phonon modes of ε-Fe
2
O
3
nanomagnets