Anomalous specific heats of soft-mode dielectrics at low temperatures
- 1 January 1977
- journal article
- research article
- Published by Taylor & Francis in Ferroelectrics
- Vol. 17 (1), 341-344
- https://doi.org/10.1080/00150197708236736
Abstract
The specific heats of the paraelectric TIBr, the ferroelectric BaTiO3, and the antiferroelectric PbZr0.95Ti0.05O3 (PZT 95/5) were measured from 2 to 37 K. Low-lying modes in all three materials result in strong maxima in CT-3. An Einstein term added to the Debye function describes the data within the experimental uncertainty (∼± 5%). Fitted Debye temperatures, θD, and average frequencies of the Einstein modes, vE, are: TlBr, 90.7 K and 22.4 cm-1; BaTiO3, 252 K and 99.3 cm-1; and PZT 95/5, 172 K and 38.1 cm-1. The Einstein modes dominate the phonon spectra at low temperatures, NE/ND ⋍ 2 to 12.Keywords
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