Microstructure and antiferroelectric-like behavior of PbxSr1-xTiO3 ceramics

The crystalline structures of PbxSr1-xTiO3 ceramics with x = 0.2-0.8 were investigated. The a- and c-axis lattice constants at room temperature were found not to be equal, corresponding to tetragonal phase when x >= 0.45, consistent with the X-ray diffraction spectra. The hysteresis loops of PbxSr1-xTiO3 ceramics were measured in different conditions, including different Pb/Sr ratio, excess Pb, sintering temperature, and maximum external electric field. It is found that the PST ceramics for x = 0.40 and 0.45 exhibit antiferroelectric-like behavior. For Pb0.45Sr0.55TiO3 ceramics, the antiferroelectric-like behavior enhanced as sintering temperature and maximum external electric field increased. Moreover, increasing excess lead content leads to abnormal hysteresis loops. The anti ferroelectric-like behavior may be described in terms of the strongly stressed hybrid structure, domain pinning and oxygen vacancy. (C) 2009 Elsevier B.V. All rights reserved.