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Quasi-2D superconductivity and Fermi-liquid behavior in bulk CaC$_6$

E. Jobiliong·H. D. Zhou·J. A. Janik·Y. -J. Jo·L. Balicas·J. S. Brooks·C. R. Wiebe
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Abstract

The intercalated graphite superconductor CaC6 with Tc ~ 11.5 K has been synthesized and characterized with magnetoresistance measurements. Above the transition, the resistivity follows a T^2 dependence up to 50 K, which suggests Fermi liquid behavior. Above 50 K, the data can be fit to the Bloch-Gruneisen model providing a Debye temperature of theta = 263 K. By using McMillan formula, we estimate the electron-phonon coupling constant of lambda = 0.85 which places this material in the intermediate-coupling regime. The upper critical field is determined parallel and perpendicular to the superconducting planes, and the dependence of the upper critical field as a function of angle suggests that this is a quasi-2D superconductivity. All of these measurements are consistent with BCS-like superconductivity.

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E. Jobiliong, H. D. Zhou, J. A. Janik, Y. -J. Jo, L. Balicas, J. S. Brooks, C. R. Wiebe. 2006-04-29. Quasi-2D superconductivity and Fermi-liquid behavior in bulk CaC$_6$. https://arxiv.org/abs/cond-mat/0604062

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