We are part of the Department
of Physics at Case Western Reserve University in Cleveland, Ohio.
MAIN RESEARCH TOPICS.
- Spintronic materials : The
idea of spintronics is to utilize the spin of the electron as well as
the charge in semiconductor devices. It faces materials challenges to
merge magnetic materials with semiconductors. Our group focuses on the
potential of transition metal and rare-earth compounds, in particular
the nitrides. This work is currently sponsored by NSF and ONR. We have
started a broad study of the magnetic, structural and electronic
properties of the transition metal nitrides. Semiconducting ScN is
studied as a potential magnetic semiconductor host. Late transition
metal nitrides such as FeN and CoN prefer zincblende structure and are
studied as potential spin -injection materials. By alloying them with
In, these can become matched to GaN. MnN and CrN are interesting
antiferromagnetic materials. In the Mn-N system we also study compounds
with other stochiometries such as ferrimagnetic Mn4N,
antiferromagnetic Mn2N and the ordered defect compound Mn3N2.
Currently we are working on incorporating calculation of
magneto-optical properties in the LMTO codes. We are also developing a
LDA+U and screened exchange approach to better deal with narrow band
magnetic materials, such as the rare earth compounds.
- Chalcopyrite
semiconductors: I-III-VI2 and II-IV-V2
compounds such as AgGaTe2, CdGeAs2, etc. We are
interested in them because of their nonlinear optical properties, which
make them useful for frequency conversion, such as second harmonic
generation, optical parametric oscillators, etc. which are used in solid
state laser systems in the mid-infra red range. Current focus is on
point defects in these materials. This work is funded by AFOSR.
- Wide-band-gap semiconductors:
Silicon carbide and Group-III nitrides, diamond. These are all useful
for high-temperature and high-power electronics and the nitrides are
promising for short wavelength electro-optic devices such as LED's and
semiconductor laser diodes. Silicon carbide is of interest because of
the polytypism. Recent work includes work on stacking fault
generation in SiC.
- High-pressure phase
transitions We study the transition paths between various
crystallographic phases and the effects of anisotropic strain. We have
developed a model for the zincblende and wurtzite to rocksalt phase
transitions.
Please send comments and suggestions
to paul.larson@case.edu
Case Physics 
