TETRAGONAL TO RHOMBOHEDRAL TRANSFORMATION IN THE LEAD ZIRCONIUM TITANATE LEAD MAGNESIUM NIOBATE LEAD TITANATE CRYSTALLINE SOLUTION

Evidence of a transformation from tetragonal to rhombohedral phases in a 80/20 mixture of lead ziconate titanate (PZT) (53/47) and lead magn esium niobate-lead titanate (PMN-PT) (65/35) was observed by x-ray dif fraction, microstructural analysis, dielectric spectroscopy, and elect rically-induced strain measurements. An increase in the electrically-i nduced strain and remanent polarization were found near 175 degrees C, which was significantly below the transition temperature (370 degrees C). Near this temperature, dielectric loss measurements revealed smal l changes, x-ray diffraction studies demonstrated a reduction in tetra gonality, and hot-stage electron diffraction patterns revealed a chang e in spot splitting along the [110]. At room temperature, bright-field imaging revealed that normal size domains coexisted with polar nanodo mains. These results are then compared to corresponding investigations of PZT and PMN-PT morphotropic phase boundary compositions. (C) 1998 American Institute of Physics.