  A comparative study of the dielectric properties and electric polarization of
multiferroics GdMn2O5 and Gd0.8Ce0.2Mn2O5 has been carried out in the
temperature range from 5 up to 300 K. The polarization properties in the
ferroelectric state that forms due to a charge ordering and exchange striction
have been studied at T less than 30 K. The properties of the restricted polar
phase separation domains formed in the crystals containing ions Mn3+ and Mn4+
have been studied, too. These domains exhibit the electric polarization in the
temperature range from 5 K to some temperatures Tf lager than TC. Such a
high-temperature polarization is due to the frozen superparaelectric state of
the restricted polar domains.
