Dielectric properties of poly- and single-crystalline BaTi 2O5

Abstract

Non-oriented and (010) oriented poly-crystalline BaTi2O 5 (BT2) was prepared by hot-pressing and arc-melting, respectively. The dielectric properties of poly-crystalline BT2 were compared with those of single-crystalline BT2 prepared by a floating zone method. The maximum permittivity of (010) oriented poly-crystalline BT 2 was 2000 at 720 K, whereas that of single-crystalline BT 2 was 6000 at the Curie temperature, Tc (750 K). The permittivity of non-oriented poly-crystalline BT2 was 30 to 300, having a small peak at 720 K. The tan δ of all specimens was 0.01 to 0.2 below Tc and significantly increased with increasing temperature above Tc. The electrical conductivity of (010) oriented poly- and single-crystalline BT2 had almost same values, which were one order higher than that of non-oriented poly-crystalline BT2 and (001) oriented single-crystalline BT2. © 2006 The Japan Institute of Metals.