A study on double hysteresis loop of antiferroelectric cupric formate tetrahydrate under hydrostatic pressure

Abstract The relations between the electric field and the polarization and between the polarization and the free energy of crystal cupric formate tetrahydrate are obtained at −20°C and -35°C under various hydrostatic pressures, and the double hysteresis loop in the antiferroelectric phase is explained in terms of a phenomenological theory.