Kinetic fragility of pure TeO2 glass

Abstract

Pure TeO2 glass was prepared in a flash differential scanning calorimeter by applying fast quenching rates to a TeO2 melt. Matching cooling and heating rates of up to 30,000 K s−1 were then used to determine the respective fictive temperatures, corresponding to viscosity values as low as 105.3 Pa s. The interdependence between calorimetric data and viscosity was verified and fine-tuned for this compositional system utilizing sodium tellurite glasses. The fragility index of pure TeO2 (m = 64) is by far the highest reported for a single-component oxide melt.