Strong electron-phonon coupling in superconductingMgB2: A specific heat study

2001/02/28 by Ch. Wälti, E. Felder, Christian L. Degen +6 · 5 citations
Materials Science · Physics and Astronomy · #Physics of Superconductivity and Magnetism #Superconductivity in MgB2 and Alloys #Thermal Expansion and Ionic Conductivity #cond-mat.supr-con

paper · pdf · doi:10.1103/physrevb.64.172515

4 pages, 4 figures

arxiv created 2001/03/03 · openalex publication_date 2001/10/16 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30

Abstract

We report on measurements of the specific heat of the recently discovered superconductor MgB₂ in the temperature range between 3 and 220 K. Based on a modified Debye-Einstein model, we have achieved a rather accurate account of the lattice contribution to the specific heat, which allows us to separate the electronic contribution from the total measured specific heat. From our result for the electronic specific heat, we estimate the electron-phonon coupling constant \ensuremathλ to be of the order of 2, significantly enhanced compared to common weak-coupling values \ensuremath\leqslant0.4. Our data also indicate that the electronic specific heat in the superconducting state of MgB₂ can be accounted for by a conventional, s-wave type BCS model.

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