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Phonon Density-of-States in MgB2

R. Osborn·E. A. Goremychkin·A. I. Kolesnikov·D. G. Hinks
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Abstract

We report inelastic neutron scattering measurements of the phonon density-of-states in Mg11B2, which has a superconducting transition at 39.2 K. The acoustic phonons extend in energy to 36 meV, and there are highly dispersive optic branches peaking at 54, 78, 89 and 97 meV. A simple Born-von Karman model is able to reproduce the mode energies, and provides an estimate of the electron-phonon coupling of lambda~0.9. The estimated boron and magnesium contributions to the isotope effect are in qualitative agreement with experiment. The data confirm that a conventional phonon mechanism, with moderately strong electron-phonon coupling, can explain the observed superconductivity.

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R. Osborn, E. A. Goremychkin, A. I. Kolesnikov, D. G. Hinks. 2001-03-02. Phonon Density-of-States in MgB2. https://doi.org/10.1103/physrevlett.87.017005

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