Temperature dependence of dielectric properties in Potassium dihydrogen arsenate crystal

Abstract

Potassium Dihydrogen Arsenate (KH2AsO4, KDA) is an inorganic arsenate ferroelectric crystal which is a KDP-family member and undergoes a ferroelectric phase transition at 96 K. A simple pseudospin lattice coupled mode model (PLCM) with some higher order terms like direct spin–spin interaction, third and fourth-order phonon anharmonic interaction terms and external electric field term, with two-time temperature dependent Green’s function technique has been employed for the evaluation of expression of response function. We can obtain and calculate soft mode frequency (Ω^), Dielectric constant (ε), and loss tangent (tanδ) expressions from response function for KDA crystal. We have shown temperature dependence of soft mode frequency (Ω^), Dielectric constant (ε), and loss tangent (tanδ) in Figs. 1-3. We have compared our findings, which seemed to be in fair alignment with experimental evidence.