Ag-Au alloys BCS-like Superconductors?

Abstract

Prompted by the recent report on the evidence for superconductivity at ambient temperature and pressure in nanostructures of silver particles embedded into a gold matrix [arXiv:1807.08572], we have exploited first principles materials discovery approaches to predict superconductivity in the 3D bulk crystals and 2D slabs of Ag-Au binary alloys at 1 atm pressure within the phonon-mediated BCS-like pairing mechanism. In calculations, it turns out that, the estimated superconducting transition temperatures of the ensued stable and metastable Ag-Au alloys resulted in Tc as low as one mK. Whereas similar calculations for the known superconducting intermetallic compounds consisting of gold, Laves Au2Bi and A15 Nb3Au predict Tc =3.6 K and 10.1 K, respectively, corroborate with experiments. And, the hitherto unknown silver analogues, Ag2Bi and Nb3Ag are also found to be superconducting at 6.1 K and 10.8 K, respectively. Furthermore, we show that, elemental Au in its metastable 9R, and hcp phases superconduct at Tc =1 mK; but not Ag, in these hexagonal lattices.

arXiv comment11, 5

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