Study of the structural insertion of Al 3+ in the Al 2O 3–SiO 2 and Nd 2O 3–Al 2O 3–SiO 2 glass systems

Abstract

Glasses in the Al 2O 3–SiO 2 and Nd 2O 3–Al 2O 3–SiO 2 systems were prepared by the sol–gel method. The gel–glass evolution was studied using near-infrared (NIR) and ultraviolet–visible (UV–VIS) spectrophotometry, X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (NMR). The results obtained indicate a relationship between the sample compositions, the treatment temperature and the Al coordination. In the samples of the Nd 2O 3–Al 2O 3–SiO 2 system the densification of the structure, when the treatment temperature increases, leads to the segregation of neodymium oxide particles.