Crystallization kinetics of the LiNbO3–SiO2–Al2O3 glass

Kinetics of crystallization in 30Li2O–30Nb2O5–35SiO2–5Al2O3 (mol%) glass were studied by the non-isothermal method using differential thermal analysis. The value of the Avrami exponent (n) was 1.4 for the sample with average particle size of 38 μm, whereas it was near 3.3 for the samples with larger particle size. These determinations led to an activation energy of about 414 kJ/mol for the bulk crystallization for this glass and about 350 kJ/mol for surface crystallization. These parameters are important for preparing transparent glass-ceramics with ferroelectric properties. X-ray diffraction analysis of the crystallized samples shows that only crystalline phase LiNbO3 formed at the first exothermic peak of the DTA curves.