Dielectric and Raman spectroscopy measurements across structural phase transition in multiferroic HoFe3(BO3)4 single crystal

Abstract

We report on findings in the HoFe3(BO3)4 single crystal across structural phase transition by the dielectric and Raman spectroscopic measurements. In most of the compounds of RFe3(BO3)4 (R=La-Lu) family low temperature P3121 structure is introduced through structural phase transition (from space group R32). Temperature dependent dielectric measurements on the HoFe3(BO3)4 crystal depicts a step like feature at the structural phase transition at ∼366 K. The Raman spectroscopy study also confirms the structural transition around this temperature. A clear signature of structural transition is reflected in the Raman spectra, mainly in the frequency range (200-400 cm-1). Appearance of new Raman modes below the transition temperature also indicates that the transition is from a high symmetry phase to a low symmetry phase.