Role of Magnetism in Superconductivity of BaFe2As2: Study of 5d Au-doped Crystals

TL;DR

This study explores how gold doping affects the magnetic and superconducting properties of BaFe2As2 crystals, revealing that 5d gold more effectively suppresses magnetism and influences superconductivity compared to 3d copper.

Contribution

It provides new insights into the role of 5d gold doping in modulating magnetism and superconductivity in BaFe2As2, highlighting the effects of local inhomogeneities and magnetic fluctuations.

Findings

Gold doping reduces magnetism more effectively than copper.

Short-range magnetic fluctuations are observed.

Local lattice inhomogeneities may hinder strong superconductivity.

Abstract

We investigate properties of BaFe2As2 (122) single crystals upon gold doping, which is the transition metal with the highest atomic weight. The Au substitution into the FeAs-planes of 122 crystal structure (Au-122) is only possible up to a small amount of ~3%. We find that 5d is more effective in reducing magnetism in 122 than its counter 3d Cu, and this relates to superconductivity. We provide evidence of short-range magnetic fluctuations and local-lattice inhomogeneities that may prevent strong percolative superconductivity in Ba(Fe1-xAux)2As2.