Study of Na2Nb2O6 and BaTiO3 glass-ceramics

Abstract Glass-ceramic systems Na2O-Nb2O5-SiO2 and BaO-TiO2-SiO2 with a small quantity of other additives (CdO, TiO2 and Al2O3, CaF2, respectively) have been studied from the point of view of their dielectric, electric and electrooptical properties in relation with the crystallinity of the samples. Glasses of the above compositions were obtained as large platelikes by quenching after melting the mixed components at high temperature and then used to nucleate ferroelectric grains which are identified by X-ray diffraction. Results of measurements of thermal depolarization currents, dielectric constant and electrooptic effect show ferroelectric behaviour as related with the grain size and crystallinity of the samples.