Comments on the dielectric discontinuties in PZT ceramics near the ferro-paraelectric transition

A new simple method to fit the temperature dependence of the spontaneous polarization by an effective field expression is discussed. This method relays upon the experimental values of Ps*, spontaneous polarization at T* > Tc, where T* is the transition temperature, and the ratio T*/Tc, from dielectric constant data, assumming h-g in the effective held expression. Data for KNbO3, PbTiO3, BaTiO3 and PZT with x(Ti) = 0.035 are analyzed and they give reasonably good fits.