Epitaxial ScFeO3 films studied by ultraviolet Raman spectroscopy

Scandium ferrite, ScFeO3 is recently discovered to be multiferroic, i.e. a material that exhibits coexisting ferroelectric and magnetic ordering. We present a study of epitaxial ScFeO3 thin films by variable temperature ultraviolet Raman spectroscopy. The 10 and 100 nm-thick films were grown by molecular-beam epitaxy on (0001) Al2O3 substrates. Room temperature Raman spectra show that ScFeO3 films have a polar hexagonal P63cm structure. The temperature evolution of the Raman spectra of a ScFeO3 film measured in the range 10–1300 K indicate a transition to a non-polar (likely P63/mmc) phase; fitting of the temperature dependence of the Raman intensities yields a transition temperature of 950±50 K. High temperature Raman spectra indicate that there may be another structural transition around 1300 K. Raman spectroscopy results are consistent with other characterization data (x-ray diffraction, second harmonic generation) obtained by our collaborators.