Microwave absorption in antiferroelectric tin chloride dihydrate crystal

Abstract

Two-sublattice pseudospin lattice coupled mode model of Mitsui [<i style="">Phys Rev, </i>111 (1958) 1259] is modified by adding along with third-and-fourth order phonon anharmonic interaction terms for SnCl₂·2H₂O crystal. With the help of double-time thermal Green's function method, expressions for shift, width, renormalized AFE soft mode frequency, Curie temperature, dielectric constant and microwave absorption are obtained for tin chloride dihydrate crystal. By fitting model values of physical quantities, temperature dependence of AFE soft frequency, dielectric constant and microwave absorption have been calculated for tin chloride dihydrate crystal. Theoretical results are compared with experimental results of Mognaschi <i>et al.</i> [<i style="">Phys Rev</i>, B14 (1976) 2005].