Calorimetric study of characteristic temperatures and crystallization behavior in Ge-As-Se-Te glass system

Results of differential scanning calorimetry of high purity Ge_xAs_40−xSe₄₀Te₂₀ (x=0-40) chalcogenide glasses are reported. The glass transition temperatures and crystallization behavior were studied under non-isothermal conditions at different heating rates (2.5-35 K/min). The glass transition temperature changes from 140 °C up to 320 °C with increasing the Ge content in Ge_xAs_40−xSe₄₀Te₂₀ glass. The studied glasses with x≤35 have no exothermal peaks of crystallization, indicating their high glass-forming ability. The glass of Ge₄₀Se₄₀Te₂₀ composition has one-stage glass transition and double-stage crystallization process during phase change. The activation energy of the glass transition (E_g), the activation energy of crystallization (E_c), the Avrami exponent (n), the frequency factor (K₀) and the crystallization criteria of Ge₄₀Se₄₀Te₂₀ glass were determined.