Strained BiFeO$_3$ films: rhombohedral-orthorhombic and rhombohedral-tetragonal phase transitions. Part IV: ultraviolet Raman spectroscopy study

ORAL

Abstract

Epitaxial BiFeO$_3$ films grown by molecular-beam epitaxy on substrates inducing different lattice-mismatch strain (YAlO$_3$, SrLaAlO$_4$, PrScO$_3$) have been studied by variable- temperature ultraviolet Raman spectroscopy. Temperature evolution of Raman spectra from BiFeO$_3$ films indicates the phase transitions from rhombohedral to tetragonal phase in compressively strained films on YAlO$_3$ and SrLaAlO$_4$ substrates. The films grown on PrScO3 substrates are subject to $\sim$1.3\% tensile strain, and undergo the transition from rhombohedral to orthorhombic phase at about 550-600 K. The temperature dependence of Raman intensities of certain characteristic peaks indicates the possibility of coexisting rhombohedral and orthorhombic phases in the temperature range 400-550 K. Raman results are consistent with the phase diagram calculated using the phase field model.

*Supported by NSF and Research Corporation for Science Advancement.

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Authors

  • Dmitri A. Tenne

    • Physics Dept., Boise State University, Boise, ID

  • A.K. Farrar

    • Physics Dept., Boise State University, Boise, ID

  • G. Molino

    • Physics Dept., Boise State University, Boise, ID

  • C. Heikes

    • Cornell University, Ithaca, NY

  • C. Adamo

    • Cornell University, Ithaca, NY

  • J.H. Lee

    • Cornell University, Ithaca, NY

  • A. Melville

    • Cornell University, Ithaca, NY

  • D.G. Schlom

    • Cornell University, Ithaca, NY

  • G. Sheng

    • Pennsylvania State University, University Park, PA

  • L.Q. Chen

    • Pennsylvania State University, University Park, PA

  • Y.-H. Chu

    • National Chiao Tung University, Hsinchu, Taiwan

  • Q. He

    • University of California, Berkeley, CA

  • R. Ramesh

    • University of California, Berkeley, CA