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arXiv · 0712.0129

A Low-Temperature Specific Heat Study of the Giant Dielectric Constant Materials

C. P. Sun·Jianjun Liu·J. -Y. Lin·Chun-gang Duan·W. N. Mei·H. D. Yang
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Abstract

Low-temperature specific-heat study has been performed on the insulating giant dielectric constant material CaCu3Ti4O12 and two related compounds, Bi2/3Cu3Ti4O12 and La0.5Na0.5Cu3Ti4O12, from 0.6 to 10 K. From analyzing the specific heat data at very low-temperature range, 0.6 to 1.5 K, and moderately low-temperature range, 1.5 to 5 K, in addition to the expected Debye terms, we noticed significant contributions originated from the linear and Einstein terms, which we attributed as the manifestation of low-lying elementary excitations due to lattice vibrations occurred at the grain boundaries and induced by local defects. Together with the findings on electronic and mechanical properties, a phenomenological model is proposed to explain the high dielectric constant behaviors at both low and high frequency regions.

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C. P. Sun, Jianjun Liu, J. -Y. Lin, Chun-gang Duan, W. N. Mei, H. D. Yang. 2007-12-02. A Low-Temperature Specific Heat Study of the Giant Dielectric Constant Materials. https://doi.org/10.1088/0953-8984%2F20%2F28%2F285214

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