Low temperature sintering and dielectric properties of Ba0.6Sr0.4TiO3–MgO composite ceramics with CaO–B2O3–SiO2 glass addition

Abstract

Self-made glass frits (calcium borosilicate glasses) were employed as the sintering aids to reduce the sintering temperatures of Ba0.6Sr0.4TiO3 (for short BST)–MgO composite ceramics. The effects of CaO–B2O3–SiO2 (for short CBS) glass on the sintering behavior, microstructures and dielectric properties of BST–MgO ceramics have been investigated. The pure BST–MgO ceramics usually sintered at above 1350°C. It was found in our experiment that 20wt.% of CBS glass additives can reduce the sintering temperature to 850°C effectively. With increasing the content of CBS glasses, both of dielectric constant (ɛr) and dielectric loss (tanδ) were decreased. The samples sintered at 850°C for 2h with 20wt.% CBS glass addition consist of Ca4Ti3O10, Mg2SiO4, and BaCa2Mg (SiO4)2 phases, and possess good dielectric properties: moderate dielectric constant ɛr=66 and small dielectric loss tanδ=2.0×10−3.