Calorimetric Analysis and Dielectric Properties of Se50Te45Ge5 Chalcogenide Alloy

摘要

In this article, the amorphous structure of chalcogenide alloy Se50Te45Ge5 is confirmed by x-ray diffraction analysis with under-constrained nature. The differential scanning calorimeter study is made for the alloy at different heating rate alpha. The T-g and T-c of the alloy are found to increase, whereas T-m appears to decrease with increasing alpha. The mean activation energy for transition and crystallization are found to be around 160 and 150 kJ/mol, respectively. The fragility index is found to decrease with the increase of alpha. The crystals are established to grow in two dimensions within the glass network. On the other hand, the dielectric constant and loss are studied at frequencies between 30 Hz and 1 MHz and at temperatures between 20 and 300 K. The dielectric modulus of the experimental data is then analyzed using different models. Suitable fitting to the practical data is attained by the application of Davidson-Cole formalism with gamma-values ranging from 0.82 to 0.99 with increasing of the temperature.