Strange Thermal Expansion of Ferroelectric TGS in the Cryogenic Temperature Region

Abstract

Recently a strange temperature dependence of the volume thermal expansion coefficient of TGS crystal has been found in the cryogenic temperature region. Therefore an electric field effect on the simultaneous measurement of the permittivity and the thermal expansion was examined under consideration of difference of a ferroelectric domain structure. The strange feature of the volume thermal expansion coefficient below 10 K was recognized again in the measurement without poling and this feature disappeared in the measurement with poling. This strange thermal expansion without poling might occur because of freezing the interaction between each area in the multi-domain state.