First-Principles Study on the Stability, Site Preference, Electronic Structure and Magnetism of Alloyed Fe3B with Ni3P-Type Structure

Abstract

First-principles calculations were performed to investigate the site preference of alloying elements, and the effect of alloying elements on stability, electronic structure and magnetism of Ni3P-type Fe3B. The calculated energies suggested that all studied compounds are thermodynamically stable while it is relatively difficult to synthesize the (Fe2.875,Cu0.125)B, (Fe2.875,W0.125)B and (Fe2.875,Nb0.125)B. The (Fe2.875,W0.125)B is the most stable compound from the view of cohesive energy. Mn element prefers to occupy the Fe2 site, whereas the others are more likely to reside in the Fe1 site. It can be found from the electronic structures that the DOSs of both Fe3B and alloyed Fe3B are dominated by Fe-d states, and all the compounds mainly contain Fe-B covalent bond, Fe-Fe covalent bond and Fe-Fe metallic bond. Based on the magnetic moments (Ms) results, it can be known that the Fe3B, (Fe2.875,Mn0.125)B, (Fe2.875,Co0.125)B, (Fe2.875,Ni0.125)B and (Fe2.875,Cu0.125)B are ferromagnetic compounds, whereas the others are ferrimagnetic compounds. Only Mn and Co are able to enhance the magnetism of Fe3B. Moreover, Mn is the most favorable candidate for improving the magnetic properties of Fe3B among the alloying elements. These results can be used to guide the composition design and performance optimization of magnetic materials containing Fe3B with Ni3P-type structure.