Pressure effect on the phase transition of trissarcosine calcium chloride

Abstract

The dielectric measurement of ferroelectric trissarcosine calcium chloride (TSCC) was made under various pressures up to 6 kbar. A striking decrease in the peak value of the permittivity, epsilon _r, at the transition temperature, T_c, was observed with increasing pressure. The value of T_c increases linearly with a pressure coefficient dT_c/dp=11.1K kbar^-1 at low pressures. This increase in T_c supports the suggestion that the ferroelectric transition is of the pure order-disorder type. It is suggested on the basis of the behaviour of epsilon _r with pressure that the order of the ferroelectric transition changes from second to first order on application of pressure.