Nitrogenrich La-Si-Al-O-N oxynitride glass structures probed by solid state NMR
2008 (English)In: Journal of Non-Crystalline Solids, ISSN 0022-3093, Vol. 354, no 1, 49-60 p.Article in journal (Refereed) Published
We investigate the local structures of oxynitride La–Si–(Al)–O–N glasses by 29Si and 27Al magic-angle spinning (MAS) solid state Nuclear Magnetic Resonance (NMR). The glasses studied span an unprecedented range of compositions, up to >50 at.% lanthanum and nitrogen out of the cations and anions, respectively, and achievable through a recently introduced glass preparation route. Transmission as well as scanning electron microscopy verified homogeneous samples over length-scales down to 20 nm. As the nitrogen content of the glasses increased, 29Si NMR evidenced a progressive formation of Si–N bonds, with SiO2N2 tetrahedra dominating in the nitrogen-rich glass networks. In the oxygen-rich end of the series, aluminum is predominantly present in tetrahedral coordination as AlO4, whereas the glasses with highest nitrogen contents have a major fraction of AlO3N structural units. Trends in isotropic 29Si and 27Al chemical shifts and 27Al quadrupolar couplings are compared with results of La–Si–Al–O glasses and are discussed in relation to the glass compositions and their proposed structures.
Place, publisher, year, edition, pages
Elsevier , 2008. Vol. 354, no 1, 49-60 p.
Oxynitride glass, La–Si–Al–O glass, Glass structure, Rare-earth Silicate, 29Si NMR, 27Al NMR, TEM, Cross-polarization, Cation distributions
Research subject Materials Chemistry
IdentifiersURN: urn:nbn:se:su:diva-24539DOI: 10.1016/j.jnoncrysol.2007.07.027ISI: 000252686600007OAI: oai:DiVA.org:su-24539DiVA: diva2:197761
Part of urn:nbn:se:su:diva-71692007-11-062007-11-062010-01-28Bibliographically approved