Formation of Complex Patterns in Refractory High-Entropy Alloys

High‑entropy alloys (HEAs) composed of multiple principal elements exhibit a remarkable diversity of microstructures, especially when refractory metals and magnetic 3d transition elements are combined. Despite extensive experimental work, the fundamental mechanisms governing the formation of such complex patterns remain insufficiently understood. In this study, we investigate microstructural evolution in tin‑containing refractory HEAs and propose a minimal theoretical model capable of reproducing the observed configurational richness. Experimentally, scanning electron microscopy reveals drastic microstructural changes induced by Sn and by the addition of Fe, Ni, Cu, or Nb. Theoret-ically, of our interest are different patterns that appear in those high entropy alloys. They consist of multiple constituents and by varying their relative concentration rich diversity of quantitatively and qualitatively different configurations could emerge. Theoretical ex-planation of these patterns generic mechanism is still lacking. In this contribution we pre-sent a minimal model that illustrates possible mechanisms yielding such configurational diversity. For this purpose, we use 2D Ising lattice model consisting of classical spins in an external transversal field Ω at temperature zero.