Effect of copper oxide amount on non-isothermal crystallization kinetics of diphosphate glasses

The present study investigates the thermal behavior and structural properties of Na2CuxZn1-xP2O7 (x = 0, 1 and 5 mol%) glasses. Differential thermal analysis (DTA) under non-isothermal conditions and X-ray diffraction (XRD) techniques were used to explore the effect of CuO amount on the crystallization kinetics of the glasses. The characteristic temperatures were used to calculate the activation energy, enthalpy, Gibbs free energy and entropy as well as morphological parameters. A correlation between the obtained results from these two techniques provides valuable information about the crystallization behavior of these glasses as well as the structural role played by the transition metal oxide. In the present glass system, CuO increased the characteristic temperatures and energies of activation and it acted as a structure modifier. Moreover, a bulk crystallization mechanism with different dimensional growth of crystals for non-doped and doped samples was obtained. The kinetic evolution was compared and confirmed using different methods.