Electrical conductivity and crystallization kinetics in Te-Se glassy system

Non-isothermal measurements of dc conductivity were used to study crystallization in bulk glasses from the TexSe100-x system (x = 10, 20, and 30). In combination with infrared microscopy, it provides a very good qualitative picture of the complex crystallization processes, as the formation of conductive paths proceeds more or less separately for each involved process. In addition, due to the pronounced signal corresponding to the surface crystallization, the dc conductivity measurements seem to bear great potential for crystallization kinetic studies. Based on identified characteristic states corresponding to the particular crystallization mechanisms, the activation energies were calculated for surface and bulk processes and compared to the differential scanning calorimetry (DSC) results reported earlier. Furthermore, the conversion rate alpha was calculated from the conductivity data by using the Odolevsky equation, the obtained dependence is in a good agreement with the results from residual enthalpies measurements performed by DSC. In a supplemental study a thorough kinetic analysis was applied to the DSC measurements of residual enthalpies. The observed decrease of the Johnson-Mehl-Avrami kinetic exponent m was explained by decrease in dimensionality of the bulk crystallization process. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4712625]