Dielectric properties and phase transition of polycrystalline lead zirconate titanate-lead cobalt niobate

摘要

The binary system of lead zirconate titanate [Pb(Zr1/2Ti1/2)O3, PZT] and lead cobalt niobate [Pb(Co1/3Nb2/3O3, PCoN] was fabricated using a high temperature solid state reaction method. The structure and homogeneity of the ceramics obtained have been investigated using x-ray diffraction. The morphology of the ceramics was characterized by scanning electron microscopy (SEM). The results indicated that the presence of PCoN in the solid solution decreases the structural stability of PZT perovskite phase. A transition from tetragonal to pseudo-cubic phase was observed as PCoN increased and the co-existence of tetragonal-pseudo-cubic phases occurred at composition with x=0.3. The permittivity showed a ferroelectric to paraelectric phase transition at 236℃ with a maximum value=39000 at 100Hz at the morphotropic phase boundary (MPB) composition.