Effect of B2O3 addition on dielectric properties and microstructure of Ba0.6Sr0.4TiO3-CuO ceramics

Abstract

This study investigates the effect of B 2 O 3 on the sintering behaviour, dielectric properties and microstructure of Ba 0.6 Sr 0.4 TiO 3 + 0.6% CuO (BSTC) ceramics. Ceramics were sintered in air at temperatures ranging from 900 to 1150°C. There are two kinds of secondary phases produced in BSTC ceramics during B 2 O 3 addition; one is BaCuB 2 O 5 with a melting point of approximately 850°C, and the other is BaTi(BO 3 ) 2 with a melting point of ³749°C. The amount of secondary phase present was seen to increase as the amount of B 2 O 3 additives increased. The BSTC ceramics with 1 mass % B 2 O 3 sintered at 1000°C in air for 2 hours exhibited a maximum permittivity, ¾ max = 1826, and a bulk density >95% of theoretical density. Moreover, 0.5 mass % B 2 O 3 doped BSTC sintered at 1000°C exhibits a maximum permittivity, ¾ max = 2100, and a bulk density >92% of theoretical density.