Spin–phonon coupling in HoCr 1 − x Fe x O 3 ( x = 0 and 0.5) compounds

We report on the temperature dependent Raman scattering studies of polycrystalline HoCr 1 − x Fe x O 3 ( x = 0 and 0.5) compounds. No signature of phonon mode related to structural phase transition is evident in the investigated temperature range in both the compounds. The thermal evolution of phonon spectra indicates a deviation of B 3g (3) mode from the expected anharmonic behaviour below magnetic ordering temperature T N in HoCrO 3 compound. This behaviour is attributed to spin–phonon coupling, which is due to the modulation of super exchange integral by lattice vibration. On the other hand, the anomalous behaviour of A g mode and its line‐width around magnetic ordering in HoCr 0.5 Fe 0.5 O 3 compound suggest the spin–phonon coupling. Apart from that, a clear deviation of wavenumber pertinent to B 2g (1) mode suggests the possibility to observe ferroelectricity in HoCr 0.5 Fe 0.5 O 3 compound. We believe that the present results would be helpful in obtaining new materials with multiferroicity near room temperature.