Crystallization behaviour of xTeO₂ - (1 -x)LiCl (x = 0.5 and 0.7 mol.) glasses

The effect of varying LiCl contents on the crystallization behaviour of the 50 mol% TeO₂ - 50 mol% LiCl and 70 mol% TeO₂ - 30 mol% LiCl glasses was investigated. Whereas crystallizing phase had a chemical composition and d-spacings close to those of the Te₆O₁₁Cl₂ phase for the glass containing 50 mol.% LiCl, paratellurite (TeO₂) was the only crystallizing phase in the 70 mol% TeO₂ - 30 mol% LiCl glasses. Surface crystallization was the predominant mechanism in both glasses and the crystals were rectangular in shape for the glass containing 50 mol. % LiCl and trigonal in shape for the glass containing 70 mol.% LiCl.