Preparation and phase formation of perovskite Pb(Ni1/3Nb2/3)O3 by a reaction-sintering process

Pyrochlore-free Pb(Ni1/3Nb2/3)O3 perovskite ceramics produced by a simple and effective reaction-sintering process were investigated. Without any calcination, the mixture of PbO, Ni(NO3)2 and Nb2O5 was pressed and sintered directly into PNN ceramics. Density of 98.5% of theoretical value was obtained after sintered at 1230 C for 2 h in air. 99.3% of theoretical density was obtained after sintered at 1,200 C for 2 h in PbO compensated atmosphere. PNN ceramic with dielectric constant 1,680 at 25 C and 1 kHz has been obtained