T^3/2 Contribution to the Specific Heat of PbTiO₃, KNbO₃ and Ba_1-xCa_xTiO₃

AT^3/2 contribution to the low temperature specific heat of anharmonic ferroelectric crystal is calculated. This may be based on domain walls contribution because it is not present in paraelectric and antiferroelectric ferroelectrics. The variation of low temperature specific heat with temperature is discussed in PbTiO3 and KNbO₃ and, the variation is discussed with defect concentration in case of Ba_1-xCa_xTiO₃ ferroelectric perovskites for different values of ‘x’.The effect of temperature and defect on low temperature specific heat can be observed in the presence of anharmonicity. Specific heat increases with increase in temperature in PbTiO₃ and KNbO₃ and, also with defect (for different concentration) in Ba_1-xCa_xTiO₃ ferroelectric perovskites.