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Indian Journal of Pure & Applied Physics (IJPAP) >
IJPAP Vol.48 [2010] >
IJPAP Vol.48(06) [June 2010] >
| Title: | Sound attenuation in Ba1-xCaxTiO3 ferroelectric perovskites |
| Authors: | Pradeep, Dushyant
Kumar, Ashok
Naithani, U C |
| Keywords: | Attenuation constant
Anharmonicity
Defect
Ferroelectrics
Curie temperature |
| Issue Date: | Jun-2010 |
| Publisher: | CSIR |
| Abstract: | Theoretical
expression of attenuation constant of anharmonic Ba1-xCaxTiO3
ferroelectric crystal in paraelectric phase using double times temperature
dependent Green’s function technique, is derived. The variation of attenuation
constant with frequency and temperature has been studied by considering third-
and fourth-order anharmonic interactions, taking electric field as an important
parameter. The mass and force constant change due to the presence of impurity
atoms in Silverman-Joseph Hamiltonian augmented with higher order anharmonic
terms. The effect of electric field, defect and anharmonicity on stabilization
of the soft mode frequency has also been studied. The attenuation constant
increases with increasing temperature and frequency in the presence of an
electric field. In the vicinity of the Curie temperature, attenuation constant
increases anomalously. |
| Page(s): | 398-402 |
| ISSN: | 0975-1041 (Online); 0019-5596 (Print) |
| Source: | IJPAP Vol.48(06) [June 2010]
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