HR: 0800h
AN: MR31B-0364 [Abstracts]
TI: Spin transition in ferrous iron in MgSiO3 perovskite under pressure
AU: * Umemoto, K
EM: umemoto@cems.umn.edu
AF: Minnesota Supercomputing Institute and Department of Chemical Engineering and
Materials Science, University of Minnesota, 421 Washington Ave SE, Minneapolis, MN 55455, United States
AU: Wentzcovitch, R
EM: wentzcov@cems.umn.edu
AF: Minnesota Supercomputing Institute and Department of Chemical Engineering and
Materials Science, University of Minnesota, 421 Washington Ave SE, Minneapolis, MN 55455, United States
AU: Yu, Y
EM: yonggang@cems.umn.edu
AF: Minnesota Supercomputing Institute and Department of Chemical Engineering and
Materials Science, University of Minnesota, 421 Washington Ave SE, Minneapolis, MN 55455, United States
AU: Requist, R
EM: Ryan.Requist@physik.uni-erlangen.de
AF: Friedrich Alexandre University, Lehrstuhl fur Theoretische Festkorperphysik
Institut fur Technische Physik III
Staudtstr. 7, Erlangen, 91058, Germany
AB:
We present a density functional study of the pressure-induced spin transition in ferrous iron in MgSiO3
perovskite. We address the influence of iron concentration and configuration (structural and magnetic), as well as
technical issues such as the nature of the exchange correlation (XC) functional (CA-LDA versus PBE-GGA) on the
spin transition pressure. Supercells containing up to 160 atoms were adopted to tackle these issues. We show
that there are preferred configurations for high-spin and low-spin iron and that the spin transition pressure
depends strongly on iron concentration and XC functionals. We also address changes of atomic structure around
Fe atoms and electronic structure including the blue shift accompanying the spin transition.
Research supported by NSF/EAR 013533, 0230319, and NSF/ITR 0428774 (VLab). Computations were
performed at the Minnesota Supercomputing Institute and Indiana Universityfs BigRed system.
DE: 3924 High-pressure behavior
DE: 3929 NMR, Mossbauer spectroscopy, and other magnetic techniques
DE: 5109 Magnetic and electrical properties (0925)
SC: Mineral and Rock Physics [MR]
MN: 2007 Fall Meeting