T. C. Upadhyay and Mayank Joshi
ABSTRACT
The third and fourth order phonon anharmonic interactions external electric field terms are added in the two -sublattice pseudospin model for PbHPO4 crystal. By using double time thermal Green’s function method modified model, theoretical expressions for soft mode frequency, dielectric constant, shift, width tangent loss and polarization are evaluated for PbHPO4 crystal. Temperature and field variations of soft mode frequency, dielectric constant and loss tangent are calculated numerically. Present theoretical results agree with experimental result of Smutney and Fousek for dielectric constant of PbHPO4.
Keywords: LHP influence, Ferroelectrics, solar-energy etc.