Powder synthesis and properties of LiTaO3 ceramics

Abstract

The LiTaO3 powders with sub micrometer grade grain size have been synthesized successfully using a molten salt method. Lithium tantalate began to form at 400°C reaction temperature and transformed to pure phase without residual reactants when it was processed at 500°C for 4h in static air. The undoped LiTaO3 ceramics with a Curie temperature about 663°C were obtained by pressureless sintering at 1300°C for 3h. The relative dielectric constant (ɛr) increases from 50 to 375 at temperature ranging from 30 to 663°C and then decreases quickly as the temperature increases above 663°C. The ceramics shows a relative dielectric constant of 49.4, a dielectric loss factor (tanδ) of 0.007, a coercive field (Ec) of 28.66kV/cm and a remnant polarization (Pr) of 32.48μC/cm2 at room temperature.