Assessment of transition-metal coordination in glasses by electron energy-loss spectroscopy -: art. no. 205111

In a combined experimental and theoretical study, it is shown that electronic structure calculations in the local density approximation on adequately sized model clusters unequivocally explain the Ti-L-2,L-3 electron energy-loss near-edge structure (ELNES) of pentahedrally coordinated Ti4+ in the fresnoite framework structure-type compound Ba2TiSi2O8. Based on an in-depth discussion of the electronic structure-ELNES relationship in crystalline matter, the highly resolved Ti-L-2,L-3 ELNES of amorphous Ba2TiSi2O8 (2BaO-TiO2-2SiO(2) glass) is interpreted in terms of Ti4+ coordination in the glass. The results demonstrate that high-resolution ELNES spectroscopy is a promising and powerful technique for atomistic-structure studies of amorphous matter.