# Ag-Au alloys BCS-like Superconductors?

## TL;DR

This study uses first principles calculations to predict superconductivity in Ag-Au alloys and related compounds, finding very low transition temperatures in bulk and 2D forms, with some known and new compounds exhibiting superconductivity.

## Contribution

It is the first to predict superconductivity in Ag-Au alloys and related compounds using first principles methods, including new potential superconductors.

## Key findings

- Ag-Au alloys have Tc as low as 1 mK.
- Known superconducting compounds like Au2Bi and Nb3Au have Tc of 3.6 K and 10.1 K.
- New predicted superconductors Ag2Bi and Nb3Ag have Tc of 6.1 K and 10.8 K.

## 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.

---
Source: https://tomesphere.com/paper/1812.09308