Spectroscopy of RFe3(BO3)4 multiferroics: phase transitions, spin-phonon interaction, coupled electron-phonon modes

Abstract

Review of the work performed in the author’s laboratory is given, on high-resolution Fourier spectroscopy studies of multiferroics from the family of rare-earth iron borates with the structure of the natural mineral huntite. For these multiferroics, we reveal spectral signatures of interactions between electronic, spin, and lattice degrees of freedom. We have observed and investigated coupled electron-phonon modes in PrFe3(BO3)4 and TbFe3(BO3)4. The structure of the magnetically ordered phase of EuFe3(BO3)4 is determined.