Crystallization Kinetics Of Sodium Niobium Silciate Glasses A. A. Zhilin Et Al

The crystallization of glasses in the Na2O-Nb2O5-SiO2 system in the temperature range 690-750°C is investigated by measuring the material density and X-ray powder diffraction analysis. It is found that the kinetics of precipitation of the NaNbO3 crystalline phase can be described by the Avrami equation with the Avrami exponent n 1. The model describing the crystallization kinetics is proposed. The crystallization of amorphous inhomogeneity regions, which are formed as a result of phase separation, is considered in the model. The consideration refers to the crystallization process governed by the nucleation of crystals in these regions. The calculated Avrami exponents are close to unity.