Effect of PMN addition on the structural, dielectric and ferroelectric properties of BT ceramics

ABSTRACTThe (1-x)BaTiO3-xPb(Mg1/3Nb2/3)O3 ((1-x)BT-xPMN) system with low content of PMN (x = 0, 0.025, 0.05 and 0.075, 0.10 and 0.15) was fabricated by a two-step conventional solid phase sintering process. X-ray diffraction analysis show that the obtained specimens possess the perovskite structure with tetragonal symmetry and undergo a sequence of phase transformations characteristic pure of BT. The microstructure study showed a dense structure, in good agreement with that of above 95% relative density determined by the Archimedes method. Electric permittivity anomaly is shifted to low temperature after PMN doping of BT. The pyroelectric and hysteresis loop measurements show that polarization and coercive field decreases after PMN doping of BT. The results obtained are discussed in terms of ions/lattice imperfections, which create local electrical and mechanical fields. The investigated ceramics are considered to be a good starting point for low-lead electronic materials.