Nonisothermal crystallization of glass-forming melts of the SeTe system

Abstract

The crystallization kinetics of Se 100−yTe y (O⩽y⩽25%) melts has been studied under the conditions of cooling the melt at a constant rate Q which influences the total value of a crystallinity degree x in a solidified substance. The x value has been determined quantitatively by DTA upon cooling vitro-crystalline samples. Experimental data x = f(y, Q) have been analyzed on the basis of the classical theory of crystallization and the concept of critical cooling rate (CCR). It has been shown that: 1) in the region of low y (< 5%) tellerium exerts a strong and complex effect on selenium crystallization; 2) the problem of a comparative crystallization ability in the series of substances-can be posed only when crystallization conditions are strictly determined (e.g., the x value, if crystallization ability is expressed as Q = f(y) for x = const); and, hence, 3) the CCR value is not a simple characteristic of the glass-forming ability of a substance.