Equilibrium phase structures for BiFeO3 thin films on LaAlO3 substrate

Abstract

The stable phase structure of BiFeO3 films on LaAlO3 substrate was studied. In the biaxial constrained case, it changes from a tetragonal phase to a rhombohedral one with the increase of film thickness. By reducing the degree of the constrain from the biaxial case to the uniaxial one, the film relaxes in a much smaller thickness to a rhombohedral phase and an enhanced piezoelectric response is predicted in comparison to that of biaxial constrained case.