LOW-TEMPERATURE DIELECTRIC-DISPERSION IN SN2P2S6

The dielectric dispersion in single crystals of stannous thiohypodipho sphate, Sn2P2S6, which shows ferroelectricity at room temperature, was measured in the frequency range between 100 Hz and 10 MHz below room temperature. We found that the non-Debye type dielectric dispersion ap pears below 100 K. From the dielectric dispersion, we determined the a ctivation energy and the attempt frequency by assuming the Arrhenius r elation. The nature of the orientational dynamics in the dipole system of Sn2P2S6 was discussed.