Investigating magnetic properties of Co68Fe4B15Si13 amorphous alloy by molecular dynamics and DFT calculations

Abstract

Cobalt-based amorphous alloys, in particular CoFeBSi, have been widely used to study the response of ac-impedance to the external dc magnetic field, i.e., the so-called Giant Magneto Impedance (GMI) effect. The utility of CoFeBSi in different applications such as field-sensitive sensors is known and practiced. Despite the wealth of experimental studies on GMI properties of CoFeBSi alloys, no computational approach has yet been addressed on electronic and magnetic properties of these systems at nanoscales. In this study, we have computed electronic and magnetic properties of amorphous CoFeBSi alloys using a combined Molecular Dynamics (MD) and Density Functional Theory (DFT) approach. MD is used to provide a physically realistic sampling of different atomic configurations while the properties such as dipole moments and magnetic susceptibilities are computed using DFT. Our study shows a wide spectrum of electronic as well as magnetic properties for nanoclusters of different sizes having implications for rational design of Co-based ferromagnetic alloys.