Field-dependent specific heats and soft modes in KTaO3and SrTiO3at low temperatures
- 1 September 1978
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review B
- Vol. 18 (5) , 2394-2396
- https://doi.org/10.1103/physrevb.18.2394
Abstract
Measurements of the electric-field dependence of the specific heats of a KTa crystal (up to 16 kV/cm) and of a SrTi ceramic (up to 22 kV/cm) at temperatures below 10 K are reported. The specific heat of both materials decreases with applied field, and the data are analyzed assuming this decrease is due to the hardening and splitting of the soft TO mode frequency. The field dependence of the soft mode is described using a Lyddane-Sachs-Teller-Devonshire formalism, and the soft-mode contribution to the specific heat is described by appropriate Einstein terms. Good agreement with the experimental data is obtained.
Keywords
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