Capturing magnetic disorder effects in complex alloys: a first-principles approach.

Capturing the finite-temperature paramagnetic state, which arises from dynamic fluctuations of local magnetic moments, requires accounting for the interplay of structural and magnetic disorder within the system. Modeling this effect in complex alloys using first-principles calculations has proven challenging due to the disparate timescales of spin and nuclear dynamics. In this work, we present a computationally tractable supercell approach, employing a superposition of static first-principles calculations, to effectively capture the effects of magnetic disorder and associated atomic relaxations. By explicitly accounting for magnetic disorder and associated atomic relaxations, we calculate point defects, planar defects, and elastic properties that are crucial material characteristics influencing the strength and phase stability of austenitic steel alloys and similar high-entropy alloys (HEAs) in the paramagnetic state. Our results demonstrate a significant impact of magnetic disorder on these material properties and, consequently, on the accurate prediction of material strength and phase stability.