Prediction of Stability, Short-range Order, and Phase Selection in Multi-Principal-Element-Alloys

We present the capabilities of KKR-CPA-based stability and short-range order (SRO) prediction in multi-component solid-solution alloys for general lattices. The refractory-based Al_xTiZrHf and Cantor-type FeMnCoCr are chosen to showcase the powerful predictive capabilities and insights found from our electronic-structure-based thermodynamic linear-response method. For AlxTiZrHf (x=1) we discovered a vacancy-mediated mechanism for phase selection driven by vacancy-atom SRO. Our X-ray diffraction data finds a variant of gamma-brass with 4 vacancies per cell (not 2, as in typical brasses), which was indicated by the calculated SRO. For fcc FeMnCoCr, we monitor energy, stacking fault energy, and SRO and find quantitative agreement with single-crystal data.