First-principles study on superconductivity of the gold–indium alloy under high pressure

Abstract

The superconductivity of gold–indium alloys has been investigated using first-principles calculations based on the density functional theory. At ambient pressure, the calculated superconducting transition temperature (T _c) is 0.04 μ K in pure gold, but T _c dramatically increases by substituting indium atoms for gold atoms. The gold–indium alloy having 12.5 atomic percent indium (Au_0.875In_0.125) shows T _c of 0.1 K, and Au_0.75In_0.25 marks 1.7 K. The dramatic increase in T _c owing to the alloying effect is caused by the enhancement of the electron–phonon coupling. The superconductivity of gold is predicted to be drastically weakened with increasing pressure and virtually disappear at 10 GPa, but it continues up to at least 30 GPa by the inclusion of indium atoms.

Keywords:

• first-principles calculation
• superconductivity
• gold
• gold–indium alloy
• phonon

Acknowledgements

This research is supported by the Japan Society for the Promotion of Science (JSPS) through its “Funding Program for Next Generation World-Leading Researchers (NEXT Program)” No. GR068 and “KAKENHI” No. 22340106.

Notes

^†This paper was presented at the L^th European High Pressure Research Group (EHPRG50) Meeting at Thessaloniki (Greece), 16–21 September 2012.