Glass-forming ability and thermal stability of Se100−x(Ge2Sb2Te5)x glassy alloys

Glassy Se 100−x (Ge 2 Sb 2 Te 5 ) x ( x = 5, 10, 15 and 20) bulk alloys were prepared by melt-quenched technique and studied by using differential scanning calorimetry at different heating rates under non-isothermal condition. The detailed thermal analysis shows that the glass transition temperature ( T g ) depends on heating rates and x content. In particular, it is found that the glass-forming ability, thermal stability ( T c − T g ) and crystallization activation energy ( E c ) increase with increased x content in amorphous Se, whereas glass transition activation energy ( E g ) and fragility index ( F ) decrease with increased x contents. Variation in these parameters can be explained on the basis of network-forming ability of Se and bonding arrangement among the constituent atoms of alloys.