Thermal Properties of Ln0.7Ca0.3CoO3 (Ln = La, Pr, and Nd) Perovskites

被引:0
作者
N. K. Gaur
Rasna Thakur
Rajesh K. Thakur
机构
[1] Barkatullah University,Superconductivity Research Lab, Department of Physics
来源
International Journal of Thermophysics | 2012年 / 33卷
关键词
Cobaltates; Specific heat; Thermal expansion; Thermal properties;
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摘要
In this article, a detailed investigation of the thermal properties of doped perovskite cobaltates Ln0.7Ca0.3CoO3 (Ln = La, Pr, and Nd) at temperatures 0 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{\rm K} \leq T \leq}$$\end{document} 350 K using the modified rigid ion model (MRIM) is presented. Theoretically, MRIM provides arguably the most realistic interaction potential to treat these properties. The variation of the specific heat and volumetric thermal expansion coefficient for these cobaltates in the temperature range 0 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{\rm K} \leq T \leq}$$\end{document} 350 K is computed. The computed specific heat is in reasonably good agreement with available experimental data. Present investigations reaffirm the presence of strong electron–phonon interactions in these compounds. The dominant contribution to the specific heat is the phonon term that follows here the Debye-type solid. In addition, the results on the temperature dependence of the molecular force constant (f), the reststrahlen frequency (υ), the Debye temperature (θD), and the Gruneisen parameter (γ0) are also discussed.
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页码:2311 / 2322
页数:11
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