Enhanced soft-to-hard magnetic switching ratio in grain-oriented Fe–Si cores induced by helical anisotropy

Abstract

The non-segmented shifted design of magnetic cores made of grain-oriented electrical steels, which induces the helical anisotropy, has been highly effective in reducing magnetic losses and minimizing acoustic noise in rotating machines. In order to address the challenges associated with precise theoretical modeling of complex underlying magnetization process, we have introduced angle-dependent first-order reversal curve diagrams. These diagrams offer significant insights into the microscopic properties of magnetization switching. By analyzing the distribution of coercive and interaction fields, we can identify distinct features that correspond to different domain wall processes and local coercivities, highlighting the magnetic behavior's heterogeneity. Through experimental measurements and theoretical analysis, we have gained quantitative understanding of the competing contributions from 90° and 180° domain wall processes in shifted structures. At shifting angles near the location of the hard magnetization axis, a notable transition in the magnetization process is observed by promoting the activation of the softer 180° domain wall processes. Among the different shifting angles tested, the structure with a shifting angle of 90° exhibits the highest ratio of soft-to-hard magnetization switching.