Abstract
Sputtered amorphous Ge4Sb1Te5, Ge1Sb2Te4, Ge2Sb2Te5, and Ag0.055In0.065Sb0.59Te0.29 thin films were studied by differential scanning calorimetry. Upon continuous heating, heat release due to structural relaxation of the amorphous phase between 0.5 and 1.0 kJ/mol was observed. This value depends on the thermal history of the sample. Preannealing of the amorphous phase revealed the glass transition temperature Tg within 10 K of the crystallization temperature upon continuous heating at 40 K/min.