Spin-dependent optical charge transfer in magnetite from optical magnetic circular diachroism
Jiunn Chen1*, Hua-Shu Hsu1, Ya-Huei Huang1, Di-Jing Huang2
1Department of applied physics, National Ping-Tung University, Ping-Tung, Taiwan
2National Synchrotron Radiation Research Center, Hsinchu, Taiwan
* Presenter:Jiunn Chen, email:asesrrc@gmail.com
In this study, we demonstrate that optical magnetic circular dichroism (OMCD) in Faraday geometry can serve as an effective means of characterizing the valence electronic structure of magnetic oxide systems. The spin-dependent channels of optical charge transfer within magnetite were resolved from transmitting OMCD spectrum. Characteristic features associated with dominant spin channels were mapped, and optical gaps of spin majority and spin minority were determined. We classified dominant optical charge transfer in magentite into three categories: (1) intervalence spin-minority d − d charge transfer relax from lattice distortion; (2) intersublattice d − d charge transfer across the valence gap of spin majority; and (3) ligand-to-metal p − d charge transfer across the valence gap of spin minority. We conclude that the transmitting OMCD spectrum can generally reflect the competition between optical transitions from the B-site Fe(3d) spin majority and the O(2p) spin minority.

Keywords: magnetite, magnetic circular dichroism , first-principle, optical charge transfer