THE EFFECT OF HYDROGEN ON THE ELECTRONIC-STRUCTURE AND PHASE-STABILITY OF IRON-BASED ALLOYS DOPED WITH CHROMIUM AND NICKEL

The electronic structures and cohesive properties of the hydrogenated face-centred cubic (FCC) and hexagonal close-packed (HCP) phases of th e CrNiFe alloy have been studied using the first-principles linear muf fin-tin orbital method combined with an x-ray diffraction study. The c ohesion energy of these crystalline phases is calculated as a function of the Wigner-Seitz radius. The predicted structure is in agreement w ith that observed experimentally and the calculated equilibrium lattic e parameters are in good agreement with the experimental values. The e lectronic structure is used to determine the relative stability of dif ferent structures. It is shown that the nature of the FCC --> HCP tran sformation in CrNiFe alloy is due to the weakening of the interatomic bond.