Structure of Nd-doped glasses measured by isotopic substitution in neutron diffraction

Abstract

The structural environment of Nd ions in glasses can have a significant effect on their performance in optical devices. Isotopic substitution in neutron diffraction has been used to probe the structure of Nd2O3 doped SiO2 and La2O3+Y2O3+Al2O3 glasses. In the silicate glass, Nd is found to be ∼sixfold coordinated by oxygen atoms at a distance of 2.28(2) Å with additional Nd–O/Si correlations at 3.55(3), 4.78(3), 5.89(3) Å, and higher distances. In the rare-earth aluminate glass a peak at 2.49(2) Å and a shoulder at ∼3 Å indicate the presence of 8 or higher coordinate Nd polyhedra by comparison with bond valence theory.