Dielectric properties of KDP-type ferroelectric crystals in the presence of external electric field

Pramana

Birendra Singh Semwal¹  Trilok Chandra Upadhyay1¹  Ramendra Singh Bhandari¹ 

[1] Physics Department, H.N.B. Garhwal University, Srinagar (Garhwal), Uttaranchal 246 174, India$$

关键词: Ferroelectrics;    pseudospin;    soft mode;    Green's function;    dielectric constant;    tangent loss.;   

DOI  :  

学科分类：物理（综合）

来源: Indian Academy of Sciences

【 摘 要 】

Considering external electric field as well as third- and fourth-order phonon anharmonic interaction terms in the pseudospin-lattice coupled mode (PLCM) model Hamiltonian for KDP-type ferroelectrics, expressions for field-dependent shift, width, renormalized soft mode frequency, Curie temperature, dielectric constant and dielectric loss are evaluated. For the calculation, method of statistical double-time temperature-dependent Green's function has been used. By fitting model values of physical quantities, temperature and electric field dependences of soft mode frequency, dielectric constant and loss have been calculated which compare well with experimental results of Baumgartner [8] and Choi and Lockwood [9]. Both dielectric constant and loss decrease with electric field.

【 授权许可】

Unknown