Dielectric and Ferroelectric Properties of Pb0.8Ba0.2[(In1/2Nb1/2)1-xTix]O3 Ceramics

Ferroelectric ceramics with formula Pb_0.8Ba_0.2[(In_1/2Nb_1/2)_{1- x} Ti _x ]O₃ (PBINT) (x=0.0, 0.05, 0.1, 0.2, 0.3, 0.4 and 0.5) were prepared via the wolframite method. The perovskite phase formation and grain morphology microstructure were examined by X-ray diffraction and scanning electron microscopy. It was found that ceramics with compositions in the range of x=0.0~0.3 showed a pseudo-cubic structure, whereas the ceramic with x=0.5 displayed a tetragonal structure. Significant frequency dispersion in the dielectric properties was observed in all compositions. However, distinct polarization vs. field hysteresis loops were found in the composition series. With increasing Ti content, remanent polarization P_r as well as coercive field E_c increase considerably. The structure analysis and properties measurement indicate that x=0.4 is the morphotropic phase boundary (MPB) composition in this system.