Site selective electronic structure analysis using EELS under channeling conditions and first principles calculations

Abstract

Combining the electron channeling effects with EELS, we could deduce site-specific electronic structures and chemical bonding. We applied this channeling EELS to Al-containing spinel and garnet crystals. The K edge spectra of octahedrally coordinated Al (Aloct) had a peak 4.5 eV higher than those of tetrahedrally coordinated Al (Altet), in both cases. However, the spinel showed broader Aloct peak width than the garnet, which was interpreted using band calculations by stronger interactions between Aloct in the spinel. These results should give essential information for designing a new optics material, by controlling the site-specific valency or spin states of solute atoms.