Preparation and property of BaTi₂O₅ ceramics by arc-melting and spark plasma sintering

摘要

In the present study, a new procedure, arc-melting followed by spark plasma sintering, was employed to prepare BaTi₂O₅ ceramics with high relative density and large dimension. Single-phased BaTi₂O₅ powders were synthesized from BaCO₃ and TiO₂ powders by arc-melting, and then the BaTi₂O₅ powders were densified by spark plasma sintering at different temperatures (1273-1473 K) and pressures (20-50 MPa). Single-phased BaTi₂O₅ ceramic was obtained at and below 1423 K, however, it tended to decompose at elevated temperatures. Considering the upperbound decomposing temperature, we further enhanced the densification of BaTi₂O₅ ceramics by increasing the sintering pressure, and a high relative density of 92.1 % was achieved at 50 MPa. The permittivity of the BaTi₂O₅ ceramics was 28.7 at 1 MHz, and increased with the measuring temperature, reaching a maximum value of 191 at the Curie temperature of ~ 740 K.