Phase separation inducing controlled crystallization of GeSe 2-Ga2Se3-CsI glasses for fabricating infrared transmitting glass-ceramics

Abstract

Infrared transmitting glass-ceramics based on the selected glass of 65GeSe2-25Ga2Se3-10CsI were obtained by a two-stage heat-treatment method. Results of X-ray diffraction and scanning electronic microscopy indicated that droplet-like nanoparticles containing cubic Ga2-δGeδSe3 crystals are homogeneously generated in the glass-ceramics and that the whole glass-ceramic process is composed of phase separation, nucleation, and crystal growth. Evolutions of the optical and mechanical properties of glass-ceramics versus annealing time at the first-stage heat treatment were also investigated. Compared with the parent glass, the fabricated glass-ceramics show considerably enhanced fracture toughness, practicable infrared transparence, and microhardness, which confer them with considerable competitive advantages over currently used infrared materials. © 2008 The American Ceramic Society.