Electrical Conductivity of KH2AsO4 and KD2AsO4

Abstract

Measurements of the electrical conductivity of K${\mathrm{H}}_2$As${\mathrm{O}}_4$ and its deuterated isomorph have been performed from room temperatures to the temperature of their respective ferroelectric transitions. Activation energies of 0.66 and 0.64 eV have been found to characterize the temperature dependence of the conductivity for K${\mathrm{H}}_2$As${\mathrm{O}}_4$ and K${\mathrm{D}}_2$As${\mathrm{O}}_4$, respectively. Further evidence that these materials display anomalously long polarization relaxation times near the temperature of their ferroelectric transition is presented and discussed. The nature of this behavior remains unexplained.