Phase transformation in (0.90−x)Pb(Mg1/3Nb2/3)O3–xPbTiO3–0.10PbZrO3 piezoelectric ceramic: X-ray diffraction and Raman investigation

Piezoelectric ceramics with compositions of (0.90−x)Pb(Mg1/3Nb2/3)O3–xPbTiO3–0.10PbZrO3, x = 0.28 , 0.31, 0.34, 0.37, 0.40 and 0.43, were prepared using the conventional columbite precursor method, and their structural phase transformation and piezoelectric behaviors near the morphotropic phase boundary (MPB) have been systematically investigated as a function of PbTiO3 content. X-ray diffraction (XRD) results demonstrate that the structure of the ceramics experiences a gradual transition process from rhombohedral phase to tetragonal phase with the increasing of PbTiO3 content, and that compositions with x = 0.34 –0.40 lie in the MPB region of this ternary system. A Raman spectra investigation of the ceramic samples testified to the transformation process of rhombohedral phase to tetragonal phase by comparing the relative intensities of tetragonal E(2TO1) mode and rhombohedral phase Rh mode. The structure information was also correlated to the parabola change of the piezoelectric constant; the maximum piezoelectric constants were obtained near the MPB region.