Crystallization Kinetics of the LiBO2-Nb2O5 Glass Using Differential Thermal Analysis.

The crystallization kinetics in the glass system (100-x) LiBO2-xNb2O5 (5≤x≤20, in molar ratio) prepared via the conventional metal-plate quenching technique have been studied by isothermal and non-isothermal methods using differential thermal analysis. X-ray powder diffraction studies carried out on heat-treated (500°C) glasses reveal the evolution of lithium niobate crystalline phase along with a minor phase of LiBO2. The exponent n in the Jhonson-Mehl-Avrami (JMA) equation applied to the isothermal process is 2.62, which is in excellent agreement with that obtained under the non-isothermal process (2.67). The activation energies for crystal growth obtained from JMA equation under isothermal condition, modified Ozawa and Kissinger equations under non-isothermal conditions, are 293, 311, and 306 kJ/mol, respectively. [ABSTRACT FROM AUTHOR]