Effect of hydrostatic pressure on the phase transitions and dielectric properties of {(CH3)2NH2}5CD3CL11

Abstract

Abstract The effect of hydrostatic pressure has been studied for the phase transition and dielectric properties of {(CH3)2NH2}5Cd3Cl11. The maximum value of the dielectric constant peak, which exists at T 1 = 280 K at 0 pressure, decreases with increasing pressure obeying a Curie-Weiss like law with the Curie-Weiss pressure of about −860 MPa. This implies that the material becomes ferroelectric at this hypothetical negative pressure. As pressure increases the first order phase transition point Tc , which exist at 127 K at 0 MPa, first decreases with dTc /dp = − 0.064 K/MPa, and then it turns to increase with dTc /dp = + 0.25 K/MPa above about 100 MPa. This indicates that there is a pressure-induced low-temperature phase above about 100 MPa.