Structural phase transformation and electrical properties of (0.90 – x)Pb(Mg 1/3Nb 2/3)O 3– xPbTiO 3–0.10Pb(Fe 1/2Nb 1/2)O 3 ferroelectric ceramics near the morphotropic phase boundary

Abstract

Novel solid solutions of (0.90 – x)Pb(Mg 1/3Nb 2/3)O 3–PbTiO 3–0.10Pb(Fe 1/2Nb 1/2)O 3, where x = 0.29, 0.31, 0.33 and 0.35, were investigated from the viewpoint of structural phase transformation, dielectric, ferroelectric and piezoelectric properties. X-ray diffraction and Raman scattering measurements demonstrated that their phase structures experienced a gradual transition process from rhombohedral to tetragonal phase near the morphotropic phase boundary (MPB) region with increasing PbTiO 3 content ( x). Corresponding to the structural phase transition near the MPB, large dielectric constants (ε r) were obtained at the compositions of x = 0.31 (ε r = 3094 at 1 kHz) and x = 0.33 (ε r = 2927 at 1 kHz). The maximum remnant polarization ( P r = 26.5 μC cm −2) was obtained at the composition x = 0.31, and the electromechanical factor ( k p = 0.59) and piezoelectric coefficient ( d 33 = 545 pC N −1) were also maximized at this composition, which indicated the enhanced electrical properties near the MPB.