Low-Temperature-Fireable Dielectric Material Pb(Fe_2/3W_1/3)O₃-(Pb, Ca)(Fe_1/2Nb_1/2)O₃ for Microwave Use

A ferroelectric Pb(Fe_2/3W_1/3)O₃-Pb (Fe_1/2Nb_1/2)O₃ (PFW-PFN) system has a low sintering temperature. A partial substitution of Ca for Pb in PFN shift the transition temperature sufficiently low, transforming this material into a paraelectric at room temperature. When paraelectric PFW-PCFN formed a single-phase (Pb, Ca)(W, Fe, Nb)O₃ (PCWFN), this material was confirmed to have a high dielectric constant with temperature stability and low dissipation loss. There was a certain amount of difficulty associated with the synthesis of single-phased PCWFN. A process to overcome this difficulty is reported. Up to now, the sintering temperature of the best characterized material was 1000°C. This temperature is very low for the sintering of a glass-free dielectric material used as a microwave resonator.