Micromagnetic analysis of magnetization reversal in Fe77.5Si7.5B15 amorphous glass-coated nanowires

Abstract

A micromagnetic model based on the finite element method (FEM) is proposed in order to investigate the specific role of the magnetoelastic anisotropy in the axial magnetization reversal process of highly magnetostrictive amorphous glass-coated nanowires with cylindrical symmetry, prepared by means of rapid quenching from the melt. Using a radially distributed magnetoelastic anisotropy term, we demonstrate that both the magnitude and the shape of the anisotropy distribution affect the value of their nucleation field, and, in well-defined cases, of their switching field. The analysis provides a good explanation framework for the characteristics of magnetic bistability in magnetostrictive glass-coated amorphous nanowires, enhancing the potential applicability of these novel ferromagnetic amorphous nanosized materials.

The Effect of Magnetoelastic Anisotropy on the Magnetization Processes in Rapidly Quenched Amorphous Nanowires

“…The developed model takes into account the dimensions (diameter and length) and the magnetic properties (the saturation magnetization M S and the exchange constant A) of these nanowires and allows one to study the dependence of the magnetization reversal process on their dimensions and, at the same time, to determine their remanence and coercivity. In the simulations, we have considered the values for highly magnetostrictive Fe 77.5 Si 7.5 B 15 amorphous nanowires: µ 0 M S = 1.6 T and A = 1.5 × 10 −11 J/m [ 23 ]. Certainly, these two parameters, saturation polarization and exchange constant, are very important for the micromagnetic model and were obtained by VSM measurements for the amorphous nanowires with the composition Fe 77.5 Si 7.5 B 15 .…”

MagTense: A micromagnetic framework using the analytical demagnetization tensor

“…However, it is possible to model other physical phenomena with a similar formalism, e.g. magnetostriction Rotarescu et al [2019] or the Dzyaloshinskii-Moriya interaction Perez et al [2014] (also called antisymmetric exchange interaction) or thermal fluctuations Ragusa et al [2009].…”