Temperature Dependence of Magnetically Active Charge Excitations in Magnetite across the Verwey Transition

摘要: We study the electronic structure of bulk single crystals and epitaxial films Fe_{3}O_{4}. Fe 2p core level spectra show clear differences between hard x-ray (HAX) soft photoemission spectroscopy (PES). The bulk-sensitive exhibit temperature (T) dependence across Verwey transition, which is missing in surface-sensitive spectra. By using an extended impurity Anderson full-multiplet model-and contrast to earlier peak assignment-we that two distinct species (A B site) charge modulation at site are responsible for newly found double peaks main above T_{V} its T-dependent evolution. HAXPES a magnetic circular dichroism (MCD) metallic phase magnetized 100-nm-thick films. model calculations also reproduce MCD identify contributions from magnetically A sites. Valence band shows finite density states E_{F} polaronic half metal with remnant order gap formation below T_{V}. results indicate transition driven by changes strongly correlated active B-site states, consistent resistivity optical