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 $\text{80/20}$ mixture of lead ziconate titanate (PZT) $\text{(53/47)}$ and lead magnesium niobate-lead titanate (PMN-PT) $\text{(65/35)}$ was observed by x-ray diffraction, microstructural analysis, dielectric spectroscopy, and electrically-induced strain measurements. An increase in the electrically-induced strain and remanent polarization were found near 175 °C, which was significantly below the transition temperature (370 °C). Near this temperature, dielectric loss measurements revealed small changes, x-ray diffraction studies demonstrated a reduction in tetragonality, and hot-stage electron diffraction patterns revealed a change in spot splitting along the 〈110〉. At room temperature, bright-field imaging revealed that normal size domains coexisted with polar nanodomains. These results are then compared to corresponding investigations of PZT and PMN-PT morphotropic phase boundary compositions.