A. C. Calorimetric Investigations of Specific Heat Anomaly in Ferroelectric TGSe
1977 年 43 巻 6 号 p. 1954-1961
詳細
1977 年 43 巻 6 号 p. 1954-1961
The specific heat of triglycine selenate was investigated with an a.c. calorimetry technique in the temperature range −170°C to +90°C including the Curie point at 22°C. A λ-type anomaly with a sharp peak at Tc was seen in the range about −60°C to Tc. The plateau region reported by Strukov et al. was not observed. The specific heat curve below Tc was fitted very well with a mean-field theory of an Ising-dipole system which took into account the effect of lattice distortion. A parameter Δ which describes the strain dependence of the interaction energy was determined to be 0.303<Δ<0.324, indicating that the transition is of the second order and very close to the Curie critical one which occurs when Δ=1⁄3. A slight excess specific heat with logarithmic temperature dependence was observed in the paraelectric phase within T−Tc\lesssim10 K. This anomaly is considered to be due to the critical fluctuation.
この記事は最新の被引用情報を取得できません。
