Dielectric Property of Single Crystalline BaTi<SUB>2</SUB>O<SUB>5</SUB> Prepared by a Floating Zone Method

Abstract

Single crystalline BaTi 2 O 5 was prepared by a floating zone method. The permittivity of single crystalline BaTi 2 O 5 perpendicular to a (010) plane showed the maximum value of 20500.at 748 K obeying the Curie-Weiss law at higher temperatures. The permittivity perpendicular to (100) and (001) planes were 140 and 70, respectively almost independent of temperature. A transition temperature measured by a dilatometer was in agreement with a Curie temperature. The relationship between polarization and electrical field perpendicular to the (010) plane showed ferroelectric hysteresis. No hysteresis was observed in the direction perpendicular to (100) and (001) planes. The electrical conductivity perpendicular to the (010) was larger than those of (100) and (001) planes. The activation energy of electrical conductivity was 147 to 180 kJ mol -1 independent of directions.