Copper oxide as a sintering agent for barium titanate based ceramics

The purpose of this work was to study the effect of CuO as a versatile sint ering agent for BaTiO3 based ceramics. The response is shown to exist in th ree directions. Firstly, as liquid-phase former at comparatively low temper atures. Hence, the influence of various CuO-based flux formers on the shrin kage behaviour and the microstructure development of the ceramics was inves tigated. Secondly, the aptitude as an internal susceptor for secondary phas e initiated microwave sintering. The use of CuO as a lossy secondary phase leads to an accelerated microwave heating of the ceramics. Thirdly, the add ition of CuO to BaTiO3 powders with Ba-excess results in a phase transition cubic --> hexagonal at about 1300 degreesC, which is a indication for the incorporation of Cu2+ ions into the BaTiO3 lattice at Ti sites under this c onditions. (C) 2001 Kluwer Academic Publishers.