Distribution of fluctuations of switching field in Fe-rich wires under tensile stress

In this paper, the distribution of fluctuations of switching field H_s in Fe_77.5B₁₅Si_7.5 amorphous wires under tensile stress is studied. The spectrum of the fluctuations of H_s for the microwires with the diameter of 125 μm is investigated. Two different mechanisms are involved in the switching process and these are domain wall pinning on metastable local defects and the magnetoelastic energy. Results show that the switching field distributions is strongly affected by the applied stress. In particular, the part of the spectrum which contains large fluctuations is strongly affected by the magnetoelastic anisotropy. On the other hand, applied stresses also affect the pair ordering mechanism related to the domain wall stabilization which gives rise to the additional energetic potential. As the stress increases, the maximal observed value of H_s increases as well, due to the positive magnetoelastic coupling constant. This means that applied stresses reinforce the switching process at lower fields.