Abstract

With the help of double-time temperature dependent Green`s function method and modifying pseudospin-lattice coupled mode model by adding third-and fourth-order phonon anharmonic interactions terms, expressions for ferroelectric mode frequency, dielectric constant and loss tangent have been derived. By fitting model values of physical quantities in above expressions, temperature dependence of above quantities have been calculated numerically. Theoretical results are compared with experimental results of others, which show agreement

Keywords

Green`s function, Pseudospin-lattice coupled mode, Anharmonic, Dielectric