Synthesis and characterization of lithium niobate ceramics with glass additions

LiNbO3 is a ferroelectric material with very high Curie temperature (T-c=1140-1210 degrees C) which has some interesting applications in electro-optical, acousto-optical, piezoelectric and nonlinear optical devices. Hence, LiNbO3 has been studied by several workers. However, less work has been reported on LiNbO3 glass-ceramics. Hence, in the present work, LiNbO3 has been synthesized by solid state sintering technique. 30Li(2)O:60B(2)O(3):10Nb(2)O(5) glass has been synthesized by the conventional melt-quenching technique. The LiNbO3 ceramics were synthesized by adding different contents of glass into LiNbO3 and sintering at different temperatures. The dielectric measurement of ceramics suggests that, 900 degrees C is the optimum sintering temperature. The frequency and temperature dependent dielectric constant of the ceramics has been studied. The LiNbO3 ceramics exhibit P-E hysteresis loop confirming their ferroelectric behaviour. The value of the remnant polarization P-r increases with glass content in the ceramics up to 7.5 wt% glass. This is supported by dielectric results which show that ceramics with 7.5 wt% glass have the optimum value of the dielectric constant.