A Physically Based Model for Soft Magnets’ Anhysteretic Curve

Abstract

The push for more efficient electromagnetic devices for energy and functional applications requires improving the existing modeling approaches of their soft magnetic components. Following the parallel that exists between fluids and magnetism, we have developed a theory to explain the isothermal anhysteretic curve of soft magnetic materials. This curve depicts the ideal lossless demagnetization path that the volume magnetization would follow in the absence of changes in the size of the magnetic domains, by the action of the external field and the so-called molecular field. We offer a discussion on the physics behind the theory. A set of plots is proposed to reveal the magnetic homogeneity of a material and the number of component magnetizations in the model. We provide illustrative examples of a nanocrystalline alloy with different induced anisotropies and a grain-oriented electrical steel under different compressive stresses. An excellent agreement of our fittings with the experimental data taken from the literature demonstrates the scientific and technical usefulness of our approach for the magnetic materials community.