Papers by Keyword: Differential Scanning Calorimerty

Abstract: In this study various compositions in the phosphate based glass (PBG) system of (50-x)P₂O₅-40Ca-(5+x)Na-5TiO₂ and (50-x)P₂O₅-40Ca-(5+x)Na-5Fe₂O₃, where x= 5 and 10 were investigated for glass transition temperature (T_g) via thermo mechanical analyser (TMA) and differential scanning calorimetry (DSC). The amorphous nature of the glasses was confirmed via XRD. The T_g measured via DSC was consistently higher by 19°C-29°C compared to TMA and was due to the thermal history and the heating rate of the samples. The T_g increased with increasing phosphate content in both glass systems. The T_g for Ti containing PBG was found to be in the range of 453°C-500°C whilst T_g for Fe containing PBG was in the range of 449°C-494°C. Consistently higher T_g for the Ti containing glass series compared to the Fe containing glasses may be attributed to the smaller ionic radius and therefore higher field strength of Ti⁴⁺.

Abstract: Phase change memory materials of Ge-Sb-Te system [(GeTe)m(Sb2Te3)n (m : n = 1:1; 1:2; 2:1)] were studied during thermal cycling by differential scanning calorimetry, and thermal properties were determined. Reproducible endothermic peak in the range of 390-415°C was revealed in Ge2Sb2Te5, GeSb2Te4, GeSb4Te7, which may possibly influence on the kinetics and endurance of data reading processes in phase-change memory devices. The nature of this endothermic peak is discussed. It was shown that additional annealing of synthesized Ge2Sb2Te5 increase stability of structure and thermal properties of the material.