Connecting the composition, structure, and magnetic property in high-entropy metallic glasses

Abstract

High-entropy metallic glasses (HE-MGs) are a new class of materials with unique properties that often exceed both those of crystalline high-entropy alloys and single-principal-element metallic glasses. In recent years, soft magnetic HE-MGs have shown excellent glass-forming ability and superb magnetic softness, thus exhibiting promising prospects. However, the lack of a sufficient understanding of composition-structure-property relationships is a major challenge for the development of HE-MGs. Here, we propose the "framework + fluctuation" model based on the Bethe-Slater (BS) curve. The model shows that in HE-MGs, metalloids will change the distribution of ferromagnetic metal atoms in the short-range (interatomic) length scale, thus affecting Curie temperature (TC) and saturation magnetic flux density (Bs) of HE-MGs. The model explains the dramatic variation of Bs caused by changing the ratio of metalloids in HE-MGs with a fixed content of ferromagnetic metal elements. The structural changes predicted by the model were further confirmed by ab initio molecular dynamics simulations. Besides providing a theoretical explanation, the model also quantitatively characterizes the effects of different metalloids on both structure and magnetic properties. The model sheds light on the role of the short-range distribution of ferromagnetic metal elements on ferromagnetism in HE-MGs, providing insights into the development of high-performance soft magnetic HE-MGs.