Dielectric Anomaly at the Phase Transition of RbD₃(SeO₃)₂

抄録

The dielectric constants ε_a, ε_b, and ε_c along the three crystallographic axes of the deuterated rubidium trihydrogen selenite RbD₃(SeO₃)₂ crystal have been measured in the temperature range including the ferroelectric phase transition. It has been found that ε_a shows a much larger peak at the phase transition than the peak of ε_b which is believed to be the dielectric constant along the polar axis in the ferroelectric phase. Some discussion for the crystal symmetry is presented in connection with the structure of the incommensurate phase.