Characterization of Fe-doped lithium aluminosilicate glass-ceramic materials by synchrotron radiation techniques

Abstract

The effects of doping of Fe ions in lithium aluminosilicate glass-ceramic under varied thermal treatment conditions were studied by synchrotron X-ray powder diffraction, X-ray absorption near edge structure (XANES) and infrared microscopy. When doping concentration is high (>0.6 wt%), Fe ions tend to migrate into the main crystalline phases; while these ions remain in a disorder environment at low doping level. In high doping samples heated at higher than 800°C, multiple scattering peaks in XANES spectra can be observed in samples, which imply that Fe ions substitute into the Li sites of the main solid solution phase. The diffraction results show that a small amount of Fe oxide (<0.2 wt%) in a LAS glass-ceramic material decreases the crystallization temperature of βquartz solid solution by ̃50°C. Samples doped with ̃0.63wt% of Fe ions results in a raised formation temperature of βquartz solid solution and a retarded phase transformation of βquartz solid solution to βspodumene solid solution. © 2012 The Ceramic Society of Japan. All rights reserved.