抄録
The anomalous ultrasonic attenuation and velocity of the longitudinal wave propagating along the b-axis perpendicular to the ferroelectric axis (c-axis) of RbHSO4 have been measured as functions of temperature and frequency near the transition temperature TC. By assuming the single relaxation process of the fluctuation induced by the ultrasonic wave at each temperature, the relaxation time τ has been analyzed. Above TC thus obtained relaxation time indicates a cross-over behavior in which the relaxation time has the exponent of n≈0.3 for T−TC<0.2°C and the exponent of n≈2 for T−TC>0.2°C. The former and the latter relaxation processes seem to be related to the energy and the polarization relaxation processes, respectively. The similar cross-over behavior has been obtained below TC.
