Polarized Raman scattering of multiferroic BiFeO3 single domian crystal and thin film

Abstract

We report the investigation of polarized Raman spectroscopy of multiferroic bismuth ferrite BiFeO3, using a ferroelectric/ferroelastic single domain crystal with an as-grown pseudo-cubic (pc) (100)pc surface and (001)pc thin film, grown by pulsed laser deposition. The polarized Raman spectra of the single crystal taken at different crystallographic orientations, agree with the rhombohedral crystal structure with C3v point group, whereas the (001)pc thin film shows monoclinic structure, contrary to the bulk-like rhombohedral and tetragonal structure as reported earlier, but consistent with the recent synchrotron radiation studies. All of the different phonon vibrations (A1 and E modes) in the single crystal have been identifield, using back polarized Raman scattering in different scattering configurations, and have unambiguously been assigned.