Phenomenological treatment of dielectric loss of ferroelectrics under hydrostatic pressure

The dielectric loss tangent in the ferroelectric phase under hydrostatic pressure is phenomenologically presented. An investigation of the effect of hydrostatic pressure on the dielectric loss tangent of iodinated trissarcosine calcium chloride is then reported. lt is found that the dielectric loss tangent in the ferroelectric phase at pressures above the transition pressure p_C (=0.38 kbar for -165°C, 1.07 kbar for -156.5°C) decreases rapidly near p_C and then gradually with increasing pressure