Piezoelectric performances of lead-reduced (1−x)(Bi0.9La0.1)(Ga0.05Fe0.95)O3-x(Pb0.9Ba0.1)TiO3 crystalline solutions in the morphotropic phase boundary

In this investigation, (1−x)(Bi0.9La0.1)(Ga0.05Fe0.95)O3-x(Pb0.9Ba0.1)TiO3(BLGF-PBT) crystalline solutions have been fabricated by using the solid-state reaction method. A ferroelectric rhombohedral/tetragonal morphotropic phase boundary (MPB) of (1−x)BLGF-xPBT was observed for x=0.4. In the vicinity of MPB, 0.6BLGF-0.4PBT revealed the maximum dielectric constant K and piezoelectric d33 constant of 1168 and 186pC∕N, respectively. The substitution of 10at.% Ba for Pb dramatically increased K and d33 of (1−x)BLGF-xPBT relative to (1−x)BLGF-xPT at the same x content. The Curie temperature Tc of (1−x)BLGF-xPBT was determined to be above 386°C through the compositions investigated. The phase diagram of (1−x)BLGF-xPBT revealed a V-shaped relationship between Tc and x content. The planar coupling coefficient Kp was measured to be 0.37 for 0.6BLGF-0.4PBT, which was stable with increasing the measurement temperature until 170°C. It is demonstrated that BLGF-PBT is a competitive alternative piezoelectric material, with the superior piezoelectricity and lead-reduced composition.