著者

Camnasio Anibal J. Gonzalo J.A.

出版者

一般社団法人日本物理学会

雑誌

Journal of the Physical Society of Japan (ISSN:00319015)

巻号頁・発行日

vol.39, no.2, pp.451-459, 1975-08-15

被引用文献数

26

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A Comparative study has been made of the specific heat in single crystals of triglycine sulfate (TGS) and deuterated triglycine sulfate (DTGS). Measurements were performed (a) in the temperature interval 100-400 K, and (b) around the respective critical regions (at small temperature intervals &sim;0.02℃). In the low temperature region, both experimental curves were almost coincident, and they showed a temperature dependence indicative of strong anomalous anharmonicity. The heats of transition (ΔQ=1.90±0.10 joule/g.) and entropy change (ΔS=(6.21±0.30)×10^<-3> joule/g℃) were almost the same for both crystals. The specific heat discontinuity was substantially different in both cases, ΔC_p=0.24±0.03 joule/g℃ for TGS, and ΔC_p=0.48±0.03 joule/g℃ for DTGS. Calculations based on both the thermodynamic theory and the statistical theory of ferroelectrics show fair agreement with the data.