Lanthanum-modified (1-x)(Bi0.8La0.2)(Ga0.05Fe0.9.)O3•xPbTiO3 crystalline solutions:: Novel morphotropic phase-boundary lead-reduced piezoelectrics

(1 - x)(Bi0.8La0.2)(Ga0.05Fe0.95)O-3.xPbTiO(3) (BLGF-PT) crystalline solutions have been fabricated by solid-state reactions. BLGF-PT has single perovskite phase structure with a rhombohedral-tetragonal (FEGamma-FEt) morphotropic phase boundary (MPB) at a PT content of x = 0.43. Lanthanum substitution has been found to increase the insulation resistance and decrease the coercive field down to 20 kV/cm, which results in significant improvements in dielectric and piezoelectric properties of BLGF-PT. The dielectric constant, loss tangent, Curie temperature, remnant polarization, piezoelectric d(33) constant, and planar coupling factor of 1760, 0.05, 264degreesC, 33 muC/cm(2) 295 pC/N, and 0.36, respectively, have been achieved for BLFG-PT in the vicinity of the MPB. Compared with conventional Pb(Zr,Ti)O-3 (PZT) piezoelectric ceramics, the BLGFPT is a competitive alternative piezoelectric material with decreased lead content.