Thermodynamic theory of the lead zirconate-titanate solid solution system, part III: Curie constant and sixth-order polarization interaction dielectric stiffness coefficients

Abstract

Vaiues of the Curie constant (C) and sixth-order polarization interaction dielectric stiffness coefficients (α₁₁₂ and α₁₂₃) are needed for the development of a thermodynamic theory for the entire lead zirconate-titanate (PZT) solid solution system. Low-temperature dielectric data measured on pure homogeneous polycrystalline PZT samples were used to determine values of these coefficients at several compositions across the phase diagram. Equations were then fitted to these data to determine the compositional dependence of the coefficients. The Curie constant was found to form a peak in the middle of the phase diagram at the PZT 50/50 composition.