High-temperature perovskite relaxor ferroelectrics: A comparative study

The recent discovery of high-temperature piezoelectric ceramics based on Bi((MeMe')-Me-')O-3-PbTiO3 solutions have also permitted the development of high-temperature relaxor ferroelectrics with ternary solid solutions. One of the high-temperature compositions based on the xBiScO(3)-yPb(Mg1/3Nb2/3)O-3-zPbTiO(3) (xBS-yPMT-zPT) ternary system exhibited a high permittivity maxima of similar to 17 000 and a T-max of 500-550 K. These materials are compared to complex lead perovskite relaxor ferroelectrics by determination of the activation energy, E-A, and freezing temperature, T-f, from the Vogel-Fulcher relationship and also a high-temperature deviation temperature, T-D, from the Curie-Weiss behavior. It was found that these parameters scale within the perovskite relaxor systems and from the self-consistent trends of these defining parameters. It is suggested that a general comparison for relaxor ferroelectrics may exist. The highest E-A, T-f, and T-D values all exist within the xBS-yPMT-zPT ternary system within the relaxor ferroelectric systems compared in this study. Furthermore, given the compositional trends within these comparisons, insights into the nature of the dynamic polarization behavior in the perovskite relaxor ferroelectrics may be gained. (c) 2007 American Institute of Physics.