Core exciton, valence exciton, and optical properties of yttrium aluminum garnet (Y3Al5O12) -: art. no. 235105

The electronic transitions from deep core levels, semicore levels, and valence bands to the empty conduction bands in yttrium aluminum garnet (Y3Al5O12) (YAG) are studied by first-principles calculations that explicitly take into account the excitonic effect. The electron energy-loss near edge structure and the valence-band optical properties thus obtained are in very good agreement with the measured optical data. The electron-hole interaction in YAG is found to be much weaker for valence-band optical transitions than for core transitions.