Low temperature sintering of CaZrO3 using lithium fluoride addition

The effects of lithium fluoride on the sinterability, the microstructure and the low frequency dielectric properties of acceptor/donor-doped CaZrO3 ceramics were investigated. The acceptor(Mn)/donor(W) doping was used to avoid CaZrO3 reduction. Lithium fluoride was selected as a liquid phase sintering aid to lower the sintering temperature. The dielectric properties of CaZrO3 ceramics with LiF additions are strongly dependent on the densification, the microstructure, and the reaction with LiF. CaZrO3 ceramics without LiF addition sintered at high temperature display a high permittivity, low losses and a good behavior under an electrical field as a function of temperature. Using LiF, this dielectric can be sintered at 1000 °C to achieve theoretical densities of 91%, εr values of 31 and losses close to 0.4%. This low sintering temperature allows co-sintering with base metal, nickel and copper, for which scanning electron microscopy and energy dispersive spectroscopy results are presented.