Fragility of chalcogenide glass in relation to characteristic temperature T0/Tg

[摘要] The present study reports the mutual relationship between the fragility index m and the characteristic temperature T0/Tg. The fragility of the chalcogenide amorphous glass of Ge10Se50Te40is calculated by utilizing glass transition temperature (Tg) measured by DSC (Differential Scanning Calorimetry) at different heating rates (β) in the range 5 to 20 K/min. Vogel-Fulcher-Tammann (VFT) equation is fitted to the data of Tg. In addition to the VFT method, three other methods are also used to evaluate m. The fragility index m of the Ge10Se50Te40system showed the trend of decrease with increasing heating rate but remained stable around 22 for the heating rate 10 K/min. The value of m for the glass is near the lower limit (m ≈ 16) this indicates the alloy is a strong glass forming material in accordance of Angell's interpretation of fragility. The calculated values of characteristic temperature T0/Tgis very close to 1 which also indicates that clearly the system is most fragile.

[发布机构] Physics Department, K J Somaiya College of Science and Commerce, Vidyavihar, Mumbai; 400077, India^1;Physics Department, Narmada College of Science and Commerce, Bharuch; Gujarat; 392011, India^2;Electronics Department, Narmada College of Science and Commerce, Bharuch; Gujarat; 392011, India^3;Physics Department, PMB Gujarati Science College, Indore; 452001, India^4

[效力级别] 机械制造

[关键词] Amorphous glass;Calculated values;Chalcogenide glass;Characteristic temperature;Dsc(differential scanning calorimetry);Fragility index;Glass forming materials;Vogel-Fulcher-Tammann equation