Phase transitional behavior and enhanced electrical properties of Bi(Sc3/4In1/4)O3-PbTiO3 by small content Pb(Mg1/3Nb2/3)O3 modification

(0.98 - x)Bi(Sc3/4In1/4)O-3-xPbTiO(3)-0.02Pb(Mg1/3Nb2/3)O-3 (BSI-xPT-PMN, x = 0.56-0.60) ternary solid solutions near the morphotropic phase boundary (MPB) have been designed and prepared using the two-step columbite precursor method. Microstructural morphology, phase transition, and electrical properties of the BSI-xPT-PMN ceramics were investigated in detail. X-ray powder diffraction analysis indicated that the BSI-xPT-PMN ceramics were of pure perovskite phase, and the MPB between the rhombohedral and tetragonal phases located at x = 0.58, which are also confirmed by their compositional dependence piezoelectric and electromechanical properties. The piezoelectric properties were enhanced significantly by the introduction of a small amount of PMN, and the piezoelectric constant d (33) is doubled that of the binary Bi(Sc3/4In1/4)O-3-PbTiO3 system. The optimal piezoelectric properties were obtained for the MPB composition 0.40BSI-0.58PT-0.02PMN, which exhibits a piezoelectric constant d (33) of 403 pC/N, planar electromechanical coupling factor k (p) of 47.2 %, remnant polarization P (r) of 36.4 A mu C/cm(2), and Curie temperature T (c) of 421 A degrees C. Additionally, the BSI-xPT-PMN systems reduce the content of Sc2O3 in comparison with the BS-PT systems. The enhanced piezoelectric performance, together with the good thermal stabilities, makes the BSI-xPT-PMN ceramics promising candidates for high temperature piezoelectric applications.