Pressure and deuteration dependence of static and dynamic properties of KDP-DKDP mixed crystals

Abstract

An explanation of the recently measured static and dynamical properties of KDP-DKDP mixed crystals is presented. The Kobayashi model for this type of ferroelectric is assumed and, under approximations justified here, the problem of disorder is reduced to a form where a theory developed by the authors in a previous paper can be applied. The virtual crystal approximation is used to study the concentration dependence of the static and dynamic properties of the mixed system both above and below the transition. Numerical results for the Curie temperature, Curie constant, saturation polarization and mixed-mode frequencies and their pressure derivatives are presented and are generally in good agreement with observation.