Combinatorial discovery of a lead-free morphotropic phase boundary in a   thin-film piezoelectric perovskite
  We report on the discovery of a lead-free morphotropic phase boundary in Sm doped BiFeO3 with a simple perovskite structure using the combinatorial thin film strategy. The boundary is a rhombohedral to pseudo-orthorhombic structural transition which exhibits a ferroelectric (FE) to antiferroelectric (AFE) transition at approximately Bi0.86Sm0.14FeO3 with dielectric constant and out-of-plane piezoelectric coefficient comparable to those of epitaxial (001) oriented Pb(Zr,Ti)O3 (PZT) thin films at the MPB. The discovered composition may be a strong candidate of a Pb-free piezoelectric replacement of PZT. 
S. Fujino, M. Murakami, A. Varatharajan, S.-H. Lim, V. Nagarajan, C.   J. Fennie, M. Wuttig, L. Salamanca-Riba, and I. Takeuchi