Pb(Ni₁/₃ Nb₂/₃)O₃ 세라믹스에 있어서 페롭스카이트상의 생성과 유전특성

Abstract

The reaction sequences of the 3PbO-NiO-Nb?O? [PNN1] and 3PbO-NiNb₂O? [PNN2] system and their dielectric properties were investigated. The pyrochlore phase of PNN1 formed in the order of Pb₃Nb₂O?, Pb?Nb₄O₁?? and Pb₃Nb₄O₁₃ according to increasing of a reaction temperature, and that of PNN2 formed only a Pb₃Nb₄O₁₃. The perovskite phase of Pb(Ni₁/₃Nb₂/₃)O₃[PNN] formed at 920℃ through the diffusion of NiO into the pyrochlore phase of Pb₃Nb₄O₁₃ on both PNN1 and PNN2, but PNN1 showed about 40% of the pyrochlore phase and PNN2 showed about 10% of it.When the samples sintered for 1 hour at 920℃ after calined for 1 hour at 850℃, the PNN1 sample showed yet about 18% of pyrochlore phase, While the PNN2 sample showed 100% of perovskite phase. The PNN2 sample(pyrochlore phase free) had a 1.5 times of maximum dielectric constant and a 0.1 times of dissipation loss(room temperature) compared to the PNN1 sample(pyrochlore phase not free)