GROWTH OF BATIO3-CE SINGLE-CRYSTALS AND THEIR PROPERTIES

BaTiO3 and BaTiO3:Ce single crystals were grown by the top-seeded solu tion growth (TSSG) technique. Instead of mechanical poling, a thermal treatment was developed to reduce the 90 degrees domains in this work. After the thermal treatment, the single crystals could be poled to th e single-domain state under an electrical field of 1kV/cm near its Cur ie temperature for 3 h. Lightly doped BaTiO3:Ce is light brown and its optical absorption increased with increasing Ce content. Electrooptic coefficients r(13)(T) and r(42)(T) were measured. A heavily doped BaT iO3:Ce appeared dark and opaque in visible light. Specific resistance rho of the heavily doped crystal in the [100] direction at room temper ature was about 80 Omega.m, and a resonance change was observed at 120 degrees C, which corresponds to the Curie temperature. This crystal s howed both ferroelectric and semiconductive properties. The concentrat ion of Ce in the crystal was found to be 2.6 times that in the melt.