Structural phase transformation and electrical properties of (0.90 - x)Pb(Mg_(1/3)Nb_(2/3))O_(3-x)PbTiO_3-0.10Pb(Fe_(1/2)Nb_(1/2))O_3 ferroelectric ceramics near the morphotropic phase boundary

摘要

Novel solid solutions of (0.90 - x)Pb(Mg_(1/3)Nb_(2/3))O_3-PbTiO_3-0.10Pb(Fe_(1/2)Nb_(1/2))O_3, where x velence 0.29, 0.31, 0.33 and 0.35, were inves-tigated 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 (epsilon_r) were obtained at the compositions of x velence 0.31 (epsilon_r velence 3094 at 1 kHz) and x velence 0.33 (epsilon_r velence 2927 at 1 kHz). The maximum remnant polarization (P_r velence 26.5 mu C cm~(-2)) was obtained at the composition x velence 0.31, and the electromechanical factor (k_p velence 0.59) and piezoelectric coefficient (d_(33) velence 545 pC N~(-1)) were also maximized at this composition, which indicated the enhanced electrical properties near the MPB.