Computer Simulation of Magnetic Properties of Fe-Ni System Bilayer Ribbons Under Bending Stress

We recently proposed Fe-Ni bilayer thin ribbons with uniaxial anisotropy using the inverse magnetoelastic effect for high-frequency driving devices. In the present study, to improve the soft magnetic properties of the ribbons, we developed a simulation method for two magnetic phases under mechanical stress. The slope of the hysteresis loop of the
$\mathrm{F}{{\mathrm{e}}_{56}}\mathrm{N}{{\mathrm{i}}_{44}}{{F}}{{\mathrm{e}}_6}\mathrm{N}{{\mathrm{i}}_{94}}$
model with stress was lower than that for no stress. This result implies that the stress induces a magnetic anisotropy, forming the hard axis in the excitation direction. As the variation of the loop by the stress was qualitatively consistent with the experimental results, we used the developed method to improve the soft magnetic properties. The simulation results suggested that reducing Fe content in the
$\mathrm{F}{{\mathrm{e}}_{56}}\mathrm{N}{{\mathrm{i}}_{44}}$
phase decreases the coercivity. Therefore, we prepared
$\mathrm{F}{{\mathrm{e}}_{{100} - x}}\mathrm{N}{{\mathrm{i}}_x}{{F}}{{\mathrm{e}}_6}\mathrm{N}{{\mathrm{i}}_{94}}$
ribbons and evaluated the coercivity. As a result, there was a significant difference in coercivity around
$x = 20$
between the experiment and simulation. Further simulation found that a factor for this difference is attributed to the deviation from the ideal layer thickness ratio of 1:1.