LAUSR

Lead-free (1- x )BiFeO 3 - x Ba 1- y Sr y TiO 3 (0 ≤  x  ≤ 0.4, 0.0 ≤  y  ≤ 0.8) (BF-BST) ceramics were fabricated with the conventional solid-state reaction method. The structural, piezoelectric, multiferroic and magnetoelectric properties have been investigated for these BF-BST solid solutions, especially for the samples near the morphotropic phase boundaries (MPB). Structural analysis shows a coexistence of rhombohedral ( R ) and tetragonal ( T ) phases in all the MPB samples, in which the lattice distortion of R and T phases increases overall and decreases, respectively, with increasing y . All the MPB samples show multiferroicity and magnetoelectric effect at room temperature. Both the ferroelectricity and piezoelectricity are found to decrease with increasing y in the MPB samples. It is revealed that high T distortion and low R distortion should contribute dominantly to the high piezoelectricity near MPB in BF-BST solid solutions. These results suggest a possible new strategy for designing high-performance piezoelectric ceramics and also the important role of MPB in the improvement of multiferroicity.