High-resolution synchrotron x-ray diffraction study of Zr-rich compositions of Pb(ZrxTi1−x)O3 (0.525⩽x⩽0.60): Evidence for the absence of the rhombohedral phase

Results of Rietveld analysis of the synchrotron x-ray diffraction data on Pb(ZrxTi1−x)O3 (PZT) for 0.525⩽x⩽0.60 are presented to show the absence of rhombohedral phase on the Zr-rich side of the morphotropic phase boundary. Our results reveal that the structure of PZT is monoclinic in the Cm space group for 0.525⩽x⩽0.60. The nature of the monoclinic distortion changes from pseudotetragonal for 0.525⩽x⩽0.54 to pseudo-rhombohedral for x>0.54.