Mechanism governing electronic charge rearrangements in random alloys

Recent work [1] has computationally investigated the statistics of internal charge distribution and transfers in metallic high entropy alloys using various first-principle approaches. It demonstrated that fluctuating internal electrostatic (“Madelung”) potentials arise generically in random alloys, due to the random environments characterizing any given lattice site. In this work, we establish the physical mechanism governing the statistics of these fluctuations, by analytically formulating an appropriate self-consistent screening theory for random system. Our theory is based on perturbative approaches to disorder, as appropriate for metallic alloys. It suggests a path to formulate an appropriate extension of standard KKR-CPA methods, which is capable of capturing the fluctuations of the internal Madelung potentials, thus providing a computationally cheap yet accurate first-principle description of high entropy alloys.

[1] M. Karabin et al., J. Mater. Sci. 57, 10677-10690 (2022).