The local structure of Sm-doped aluminosilicate glasses prepared by sol–gel method

Abstract

The local structures of Sm and Al in Sm-doped aluminosilicate glasses prepared by the sol–gel method were investigated by using 27Al MAS NMR spectroscopy and X-ray radial distribution function (RDF) analysis. It is found that at low alumina content (1 mol%), the glass network consists of SiO 4 and AlO 6 structural units. At higher alumina content, AlO 4 and AlO 6 structural units coexist in the glasses. It is considered that the formation of AlO 4 results in enhancement of the dispersion of Sm ions in these glasses. The average coordination number of Sm in a 10Al 2O 3 · 90SiO 2 · 1Sm 2O 3 glass slightly increased from 7.1 to 8.5 after heat-treatment in reducing atmosphere. The role of Al ions in dispersing Sm ions in a glass matrix is discussed.