Gettering of S in Ni from first principles

Sulphur segregation to grain boundaries, surfaces or interfaces seriously degrades the performance of many metallic systems. The addition of appropriate dopants may reduce the sulphur effect. Here we present a first-principles study to provide physical insights into Hf and Pt interactions with S in Ni. The pair affinities are assessed through total energetics, electron localization function and differential charge density analyses. Calculations show that Hf can effectively getter S and hence inhibit S segregation even at high temperatures, while Pt cannot.