A two sub-lattice pseudospin-lattice coupled mode model along with third and fourth order phonon anharmonic interactions terms is considered for Rochelle salt. Double Time temperature dependent Green?s function method is used for development. Expression for shift, width, renormalized soft mode frequency, Curie temperature, dielectric constant and loss tangent have been derived. Model values of physical quantities are fitted. Theoretical results were compared with experimental results of literature, which show a good agreement
Ferroelectrics, Soft mode, Green function, Anharmonic interactions