  Polycrystalline samples of CuCrO2 were synthesized by solid state reaction
method. Temperature dependent dielectric measurements, synchrotron x-ray
diffraction (SXRD), pyroelectric current and Raman measurements have been
performed on these samples. Evidences of the presence of relaxor type
ferroelectricity, which otherwise have gone unnoticed in CuCrO2 system (a
member of delafossite family) near room temperature, have been presented.
Presence of broad maximum in dielectric permittivity and its frequency
dispersion indicates relaxor-type ferroelectricity in CuCrO2 near room
temperature. Careful analysis of temperature dependent SXRD data and Raman
spectroscopic data indicates that the distorted CrO6 octahdera, is giving rise
to strain in the sample. Due to this strain, polar regions are forming in an
otherwise non-polar matrix, which is giving rise to relaxor type
ferroelectricity in the sample. Regularization of CrO6 octahedra and
disappearance of disorder induced peak in Raman spectra at high temperatures
could be the reason behind observed dielectric anomaly in this sample. Present
investigations propose that relaxor type ferroelectricity near room temperature
is an inherent property of the CuCrO2 system, making it a fascinating material
to be explored further.
