Low-firing PZN-PFN-PFW relaxor ferroelectric ceramics produced by a reaction-sintering process

Pb((Zn1/3Nb2/3)0.16(Fe1/2Nb1/2)0.48(Fe2/3W1/3)0.36)O3 (PZFNW) relaxor ferroelectric ceramics produced by a reaction-sintering process of low sintering temperatures were investigated. Without any calcination, the mixture of PbO, Zn(NO3)2, Fe(NO3)3, Nb2O5 and WO3 was pressed and sintered directly. PZFNW ceramics of 100% perovskite phase were obtained after sintering at 830-950 °C. A density of 8.66 g cm−3 (98.6% of theoretical value) was obtained after sintering at 930 °C for 2 h. Grain sizes of 2-7 and 3-12 μm were formed after sintering at 830-950 °C for 2 and 4 h, respectively. The dielectric constant for 1 kHz at room temperature increases with sintering temperature and reaches the value of 17,400 at 930 °C due to the increased density and grain size.