PNNL

Abstract

Magnetic contributions have the potential to significantly influence predicted phase stability within alloy mixing phase diagrams, yet have been historically challenging to incorporate due to a significant increase to phase space sampling. In this work, we examine a computational protocol that includes spin orientation as an additional configurational component within multi-component cluster expansions between magnetic and non-magnetic metal alloys (calculated using density functional theory (DFT) and the generalized gradient approximation). Corundum:eskolaite and corundum:hematite mixtures were used as test cases. Two-component cluster expansions of non-magnetic Al(III) and ferromagnetic Cr(III) and Fe(III) were performed, and a phase diagram was calculated for later comparison. Finally, a non-magnetic Al(III) and \up" and \down" magnetic configuration for anti-ferromagnetic Cr(III) and Fe(III) were performed. Magnetic contribution to the calculated phase diagram for the corundum:eskolaite system was shown to be inconsequential, yet absolutely vital for corundum:hematite.