PMN-PFN Relaxor Ferroelectric Ceramics by a Reaction-Sintering Process

Pb((Mg_1/3Nb_2/3)_0.6(Fe_1/2Nb_1/2)_0.4)O₃ (PMFN) perovskite relaxor ferroelectric ceramics produced by reaction-sintering process were investigated. Without any calcination, the mixture of PbO, Mg(NO₃)₂, Fe(NO₃)₃ and Nb₂O₅ was pressed into pellets and sintered directly. PMFN ceramics of 100% perovskite phase were obtained. Density of 7.84 g/cm³ (95% of theoretical value) was obtained after sintered at 1250°C for 2 h. Grain sizes of 3–6 m were formed after 2 h sintering at 1150–1250°C. Dielectric constant at room temperature under 10 kHz reaches 22400 after sintered at 1250°C for 2 h.