Temperature dependence of microwave loss in rochelle salt crystal

Abstract

Considering two-sublattice pseudospin lattice coupled mode model [Chaudhuri et al., J Phys Soc Jpn, 49(1980) 609] along with third-and fourth-order phonon anharmonic interaction terms and using double-time thermal Green's function method, expressions for shift, width, renormalized soft mode frequency, Curie temperature, dielectric constant and microwave absorption have been derived and discussed for rochelle salt crystal. By fitting model values of physical quantities, soft mode frequency, dielectric constant and microwave loss tangent have been calculated. Theoretical results compare well with experimental results of Sandy and Jones, Phys Rev, 168 (1968) 481.