Unraveling the mystery of the tricritical point in Zr-rich PbZr1-xTixO3

The solid solution of lead titanate (PbTiO3) and lead zirconate (PbZrO3), known as PbZr1-xTixO3 (PZT), is commonly used in a wide range of applications because of its high piezoelectric and coupling coefficient. The morphotropic phase boundary (MPB) has been widely studied by lots of researchers including us. Recent study shows tricritical behaviour in the high-Zr (x ~ 0.06) region. Unusual anomalies have been observed with Curie temperature, dielectric constants etc. as a function of composition. Our recent diffuse scattering results on single crystals suggest that the structure here is of lower symmetry than previously thought. In order to investigate the high-temperature and room-temperature structures and phase changes around this tricritical point, we request four days of HRPD time to collect full patterns with x = 0.02, 0.04, 0.05, 0.06, 0.07, 0.08, 0.10 at various temperatures.