Crystallization studies on bulk Si_xTe_100-x glasses

Abstract

Bulk Si_xTe_100-x (10 ≤ x ≤ 28) glasses have been prepared by the melt quenching technique. The crystallization of these glasses has been studied by using differential scanning calorimetry. The composition dependence of the glass transition temperature T_g, the recrystallization temperature T_cr and the melting temperature T_m show an unusual behaviour at the composition x ≅ 20. The glasses with 10 ≤ x ≤ 20 undergo double glass transition and double stage crystallization phenomena. On the other hand, glasses with 22 ≤ x ≤ 28 exhibit eutectic crystallization. The phases at different stages of crystallization have been identified by using X-ray diffraction techniques. The unusual behaviour at x ≅ 20 can be explained on the basis of the changes in the network topologies of IV-VI chalcogenide glasses.