Hierarchical geometric designs for Fe-based amorphous materials with tunable soft magnetic properties

Tailoring the soft magnetic properties of magnetic materials is highly desired from both academic and technological standpoints. In this study, we propose an alternative approach to manipulate the magnetic susceptibility and related properties of soft magnetic materials by geometric designs. For example, porous honeycomb structures of Fe92.9C3.5Si3.6 amorphous ribbons are fabricated with control over the wall width, which ranges from 60 to 130 μm. The magnetic field dependence of the magnetization shows that the magnetic susceptibility strongly depends on the wall width of porous honeycomb structures, i.e., the smaller the width, the higher the susceptibility. In addition, the susceptibilities of porous honeycomb structures are larger than that of their continuous counterpart. The geometrical dependence of the magnetic susceptibility is confirmed by phase field modeling. The simulation results suggest that a high density of domain walls can be accommodated in a porous honeycomb structure with a small wall width. Thus, the transitions of domain configurations under the magnetic field can be tailored, which brings about a geometrical dependence of the magnetic susceptibility. The present work opens a broad avenue for the geometric design of magnetic properties.