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Indian Journal of Pure & Applied Physics (IJPAP) >
IJPAP Vol.48 [2010] >
IJPAP Vol.48(08) [August 2010] >
| Title: | Temperature dependence of soft mode frequency, dielectric constant and loss tangent in PbHPO4 crystal in presence of electric field |
| Authors: | Upadhyay, Trilok Chandra
Joshi, Mayank |
| Keywords: | Dielectric constant
Ferroelectric
Green’s function
Anharmonic interactions |
| Issue Date: | Aug-2010 |
| Publisher: | CSIR |
| Abstract: | An extended two
sublattice pseudospin lattice coupled mode model by adding third and
fourth-order phonon anharmonic interactions terms as well as external electric
field term has been considered for lead hydrogen phosphate crystal and its
isomorphs. With the help of double-time temperature dependent Green’s function
method, theoretically, expressions for shift, width, soft mode frequency,
dielectric constant and loss tangent are derived. By fitting model values in
the theoretical expressions, temperature and electric field dependence of soft
mode frequency, dielectric constant and loss tangent is calculated for PbHPO4
crystal in presence of electric field. The theoretical results compared with
experimental results of Smutny and Fousek [Ferroelectrics,
21 (1978) 385] show good agreements. |
| Page(s): | 550-555 |
| ISSN: | 0975-1041 (Online); 0019-5596 (Print) |
| Source: | IJPAP Vol.48(08) [August 2010]
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