Phase transformation in (0.90 - x)Pb(Mg_(1/3)Nb_(2/3))O_(3-x)PbTiO_3-0.10PbZrO_3 piezoelectric ceramic: X-ray diffraction and Raman investigation

摘要

Piezoelectric ceramics with compositions of (0.90 - x)Pb(Mg_(1/3)Nb_(2/3))O_(3-x)PbTiO_3-0.10PbZrO_3, 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 PbTiO_3 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 PbTiO_3 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(2TO_1) mode and rhombohedral phase R_h, 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.