Structure and ion transport pathways in 0.45Li2O-(0.55-x)P 2O5-xB2O3 glasses

Abstract

Lithium borophosphate glasses 0.45Li2O-(0.55-x)P 2O5-xB2O3 (where 0 ≤ x ≤ 0.40) were investigated focusing on the influence of cation mobility changes due to mixed glass former effect. It was found that glass transition temperature (Tg) increases and molar volume decreases with B2O 3 addition. X-ray photoelectron spectroscopy (XPS) spectra showed that besides P-O-P, B-O-B and P=O, P-O-, B-O- bond peaks, an intermediate O1s peak due to P-O-B bonds emerges in glasses with B 2O3 contents x ≥ 0.15. Molecular dynamics (MD) simulations for the same systems have been performed with an optimized potential, fitted to match bond lengths, coordination numbers and ionic conductivity (σdc). Structural effects on ion transport as the origin of the mixed glass former effect can be quantified by applying the bond valence analysis (BV) approach to the equilibrated MD trajectories. © 2010 Materials Research Society.