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Heat Capacity of MgB_2: Evidence for Moderately Strong Coupling Behavior

R. K. Kremer·B. J. Gibson·K. Ahn
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Abstract

We characterize the superconducting state of phase pure polycrystalline samples of the new layered superconductor MgB$_2$ by specific heat measurements in magnetic fields up to 9 T. The characteristic jump at the superconducting transition is observed and compared with the predictions of weak coupling BCS-theory and the $α$-model. Our analysis shows excellent agreement with the predictions for 2$Δ/k_BT_{\rm C}$ = 4.2(2) with a Sommerfeld term $γ_{\rm exp}$ of 3.1(1) mJ/mol K$^2$ indicating that MgB$_2$ is a superconductor in the moderately strong electron-phonon coupling regime.

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R. K. Kremer, B. J. Gibson, K. Ahn. 2001-04-17. Heat Capacity of MgB_2: Evidence for Moderately Strong Coupling Behavior. https://arxiv.org/abs/cond-mat/0102432

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