Theory of Dielectric Susceptibility of RDP–ADP Mixed Crystals

Abstract

The cluster theory which is developed to describe the glassy phase of Rb_1−x(NH₄)_xH₂PO₄ is extended to explain the anomalous behaviour in the dielectric susceptibility χ of this phase. It is shown that χ begins to deviate from the normal value of the paraelectric phase at and below the glass transition temperature T_g, and the deficient part of the susceptibility below T_g is precisely proportional to the glass order parameter properly redefined.