The role of CuO-MOx in low-fire high dielectric ceramics for multilayer capacitors

Abstract

CuO-based oxide mixtures were selected as sintering aid for (Ba,Ca)(Ti,Zr)O-3 ceramics. Both microstructure and dielectric properties of were remarkably influenced by BaCO3-CuO flux type. With 1 wt % additive of BaCuO2-2.5CuO eutectic phase, (Ba,Ca)(Ti,Zr)O-3 ceramics give high dielectric constant of 11000 and uniform grain size of 4 - 10 mu m when sintered at 1130 degrees C for 1 h. Different kinds of CuO-MOx mixtures were also used to investigate the role of MOx metal oxide in the grain growth and densification of CuO-added (Ba,Ca)(Ti,Zr)O-3 ceramics. The eutectic temperature between CuO and MOx plays an important key in microstructure evolution. Both dielectric properties and microstructure can be further modified with doping secondary oxides.