Theoretical investigation of superconductivity in ternary silicide NaAlSi with layered diamond-like structure
Taylor & Francis
This is the author accepted manuscript. The final version is available from Taylor & Francis via the DOI in this record.
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© 2016 Informa UK Limited, trading as Taylor & Francis Group.We have investigated the electronic structure, phonon modes and electron-phonon coupling to understand superconductivity in the ternary silicide NaAlSi with a layered diamond-like structure. Our electronic results, using the density functional theory within a generalized gradient approximation, indicate that the density of states at the Fermi level is mainly governed by Si p states. The largest contributions to the electron-phonon coupling parameter involve Si-related vibrations both in the x-y plane as well as along the z-axis in the x-z plane. Our results indicate that this material is an s-p electron superconductor with a medium level electron-phonon coupling parameter of 0.68. Using the Allen-Dynes modification of the McMillan formula we obtain the superconducting critical temperature of 6.98 K, in excellent agreement with experimentally determined value of 7 K.
Philosophical Magazine, 2016, Vol. 96, Number 10, pp. 1006 - 1019