Preparation of the Oriented Polycrystalline BaTi2O5 Ferroelectric Ceramics

Abstract

ABSTRACT:The dense and oriented BaTi 2 O 5 (BT 2 ) in a single phase was successfully obtained by an arc melting process on a water-cooled copper plate using BaCO 3 and TiO 2 as starting materials and B 2 O 3 as an additive. XRD pattern of BT 2 showed a preferred orientation of (020). The microstructure of BT 2 was examined to show a needle-like shape and the BT 2 grains were 3~15 µm in diameters and 22~110 µm in lengths. Though B 2 O 3 was effective to prepare dense BT 2 , it, disadvantageously, tended to decrease the permittivity of BT 2 . The discrepancy of the peak frequencies between Z″ and M″ could be ascribed to the existence of structural defects and occurrence of the second phase. The maximum permittivity was 863 when the frequency (f) and the Curie temperature (T c ) were 100 kHz and 465°C, respectively.