Structure of Rare-Earth Aluminosilicate Glasses Probed by Solid-State NMR Spectroscopy and Quantum Chemical Calculations

Sammanfattning: Aluminosilicate glasses incorporating rare earth elements feature highly beneficial physical and chemical properties, at the level beyond that accessible for compositions based on alkali and/or alkaline earth metals. Extraordinary hardness, high glass transition temperatures and indices of refraction, favorable coefficients of thermal expansion, as well as excellent chemical durability, result in many potential technological applications. However, in contrast to the systematically explored and commercially exploited aluminosilicate glasses that contain Na, K, and Ca elements, their rare earth counterparts were sparsely investigated, although exhibit several unique structural features.This thesis explored the short- and medium-range structural organization of glasses belonging to the ternary RE2O3—Al2O3—SiO2 systems, where RE denotes one of the trivalent and diamagnetic rare earth metal ions of scandium (Sc), yttrium (Y), lanthanum (La), and lutetium (Lu). Comprehensive multinuclear solid-state nuclear magnetic resonance studies complemented with atomistic molecular dynamics computer simulations and quantum chemical calculations provided detailed insight into local environments of the glass networkforming elements (Si, Al), oxygen species, as well as the rare earth ions, thereby offering a deeper understanding of the glass structure.