Effect of Pressure on Superconducting Ca-intercalated Graphite CaC${}_6$

Abstract

The pressure effect on the superconducting transition temperature ($T_c$) of the newly-discovered Ca-intercalated graphite compound CaC${}_6$ has been investigated up to $\sim$ 16 kbar. $T_c$ is found to increase under pressure with a large relative ratio $\Delta$$T_c$/$T_c$ of $\approx$ +0.4 %/kbar. Using first-principles calculations, we show that the large and positive effect of pressure on $T_c$ can be explained in the scope of electron-phonon theory due to the presence of a soft phonon branch associated to in-plane vibrations of Ca atoms. Implications of the present findings on the current debate about the superconducting mechanism in graphite intercalation compounds are discussed.

6 pages, 5 figs, final PRB version

References in corpus (12)

• Kohn Anomalies and Electron-Phonon Interaction in Graphite
• Superconductivity in the Intercalated Graphite Compounds C6Yb and C6Ca
• Superconductivity of bulk CaC6
• Superconductivity in lithium, potassium and aluminium under extreme pressure: A first-principles study
• Intercalant-Driven Superconductivity in YbC${}_6$ and CaC${}_6$
• Superconductivity and Lattice Instability in Compressed Lithium from Fermi Surface Hot Spots
• Scanning Tunneling Spectroscopy on the novel superconductor CaC6
• Specific Heat of the Ca-Intercalated Graphite Superconductor CaC${}_6$
• Experimental evidence of s-wave superconductivity in bulk CaC${}_6$
• Possibility of superconductivity in graphite intercalated with alkaline earths investigated with density functional theory
• Electrons and phonons in the ternary alloy CaAl${}_{2-x}$Si${}_x$} as a function of composition
• Pressure dependence of the superconducting transition temperature in C${}_6$Yb and C${}_6$Ca

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