Phase coexistence near a morphotropic phase boundary in Sm-doped BiFeO3 films

We have investigated heteroepitaxial films of Sm-doped BiFeO3 with a Sm-concentration near a morphotropic phase boundary. Our high-resolution synchrotron x-ray diffraction, carried out in a temperature range of 25 to 700 degrees C, reveals substantial phase coexistence as one changes temperature to crossover from a low-temperature PbZrO3-like phase to a high-temperature orthorhombic phase. We also examine changes due to strain for films exhibiting anisotropic misfit between film and substrate. Additionally, thicker films exhibit a substantial volume collapse associated with the structural transition that is suppressed in thinner films. (c) 2010 American Institute of Physics. [doi:10.1063/1.3481065]