Crystallization of K2O-TiO2-SiO2 glass below glass transition by poling

Abstract The Raman technique and X-ray diffractometry are used to study the crystallization of potassium-titanosilicate glass under thermal poling. It is shown that one of the crystalline phases of titanium dioxide, anatase, is formed in the subsurface layer of the glass under the anode. During subsequent heat treatment, it partially transforms into a more thermodynamically stable phase that is rutile. The crystallization occurs at the poling temperature of ~ 460 °C, which is below the glass transition temperature, 485 °C, and below the crystallization temperature of binary glasses xTiO2-(1-x) SiO2 and films of similar composition. The mechanism of the formation of the crystalline phase is discussed.