Synchrotron X-ray Study of Thin Film Samarium Doped BiFeO3 at the Morphotropic Phase Boundary

ORAL

Abstract

Samarium doped bismuth ferrite (BSFO) is a good lead free candidate for piezoelectric applications. For Sm concentrations of $\sim $14{\%}, BSFO is at a morphotropic phase boundary (MPB) between two structural phases much like lead zirconium titanate (PZT). We have conducted a high resolution synchrotron x-ray diffraction study of Sm doped BiFeO3 films at a composition near the MPB. Films of varying thicknesses were studied over a temperature range of 25C to 700C. We found that the mixed phases associated with the MPB vary with temperature and thickness, indicating that they undergo a transition near 275C. Fundamental lattice constants were measured as a function of temperature; additionally this allowed us to probe structural twins. Also, thermal history dependence was found that indicates a chemical change occurring above film growth temperature.

*This work was funded by NSF grants DMR-0907197, DMR-0603644, DMR-0520471, ARO grant W911NF-07-1-0410, the Australian Research Council ARC Discovery Project, a DEST ISL grant, and support from the W.M. Keck Foundation and NEDO

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Authors

  • Daisuke Kan

    • Department of Materials Science and Engineering and Center for Superconductivity Research, University of Maryland, College Park, MD 20742
    • University of Maryland

  • Samuel Emery

    • University of Connecticut

  • Barrett Wells

    • University of Connecticut

  • Ching-Jung Cheng

    • University of New South Wales

  • Nagarajan Valanoor

    • University of New South Wales

  • I. Takeuchi

    • University of Maryland
    • Department of Materials Science and Engineering and Center for Superconductivity Research, University of Maryland, College Park, MD 20742
    • Univ. of Maryland