  We have carried out the ESR study of the multiferroic triangular
antiferromagnet CuCrO2 in the presence of an electric field. The shift of ESR
spectra by the electric field was observed; the observed value of the shift
exceeds that one in materials with linear magnetoelectric coupling. It was
shown that the low-frequency dynamics of magnetically ordered CuCrO2 is defined
by joint oscillations of the spin plane and electric polarization. The results
demonstrate qualitative and quantitative agreement with theoretical
expectations of a phenomenological model (V.I. Marchenko (2014)).
