Effect of hydrogen on surface energy of fcc Fe alloys: A first-principles study

Aiming at revealing hydrogen (H) – materials interactions, the present theoretical work investigates the effect of H on the (111) surface energy (, and in actual fact the fracture free energy was studied herein) of Fe-rich fcc binary alloys FeX and FeX and ternary alloy FeCrNi, where X represents 31 alloying elements including Al, Co, Cr, Cu, Mn, Mo, Ni, V, W, and Zn. These values were predicted by density functional theory (DFT) based first-principles calculations using the nonmagnetic (NM, the present focus), ferromagnetic (FM), and antiferromagnetic (AFM) configurations. Correlation analysis reveals that the volume of X () is a predominant descriptor to model with with the goodness-of-fit R = 0.943 for the case of NM FeX. It is found that hydrogen adsorption decreases , i.e., increasing H-coverage on the surface of fcc Fe alloys decreases nearly linearly for most alloys. We further found that increases initially and then decreases with increasing volume for each alloy, implying that for Fe alloys with less H-coverage, decreases with increasing temperature.