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Indian Journal of Pure & Applied Physics (IJPAP) >
IJPAP Vol.48 [2010] >
IJPAP Vol.48(04) [April 2010] >
| Title: | Dependence of specific heat on electric field in Ba1-xCaxTiO3 ferroelectric perovskites |
| Authors: | Pradeep, Dushyant
Kumar, Ashok
Naithani, U C |
| Keywords: | Anharmonicity
Curie temperature
Defects
Soft mode frequency
Specific heat
Ferroelectric perovskites |
| Issue Date: | Apr-2010 |
| Publisher: | CSIR |
| Abstract: | The electric field
dependence of the specific heat of an anharmonic Ba1-xCaxTiO3
ferroelectric crystal has been calculated in its paraelectric phase from
Silverman-Joseph Hamiltonian augmented with fourth order phonon coordinates
using double times Green’s functions. The electric field dependent soft mode
contribution to the specific heat is described by appropriate Einstein terms.
The variation of the specific heat with temperature and defect parameters has
been discussed for different values of field strengths. The effect of defects
on specific heat can be observed in the presence of anharmonicity. The specific
heat decreases with increase in external field and increases with increase in
temperature which is in agreement with the previous results. As the Curie
temperature is approached, the Cochran soft mode is held to be responsible for
the anomalous behaviour of specific heat. |
| Page(s): | 276-281 |
| ISSN: | 0975-1041 (Online); 0019-5596 (Print) |
| Source: | IJPAP Vol.48(04) [April 2010]
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