Dynamics of magnetic field penetration into soft ferromagnets

• Published in: Journal of applied physics Vol. 117; no. 24
• Main Authors: Ducharne, B., Sebald, G., Guyomar, D., Litak, G.
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 28.06.2015
• Subjects: Applied physics; Domain walls; Eddy currents; Engineering Sciences; Ferromagnetism; Hysteresis loops; Hysteresis models; Magnetic domains; Magnetic fields; Operators; Penetration; Frequency dependence; Surface excitations; Fractional operators; Ferromagnetic materials; Single sheet testers; Hysteresis loops; Magnets; Magnetic field diffusion; Fractional derivative operator; Magnetic domains; Problem solving; Ferromagnetism; Magnetic materials; Magnetism; Diffusion; Magnetic fields; Eddy currents; Magnetic field penetrations; Frequency dependent; Hysteresis
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.4923162

We propose an approach to solve the coupled problem of the magnetic field penetration into soft ferromagnets and a frequency dependent magnetic hysteresis. The magnetic field diffusion is related to the macroscopic eddy currents. The hysteresis model is related to the microscopic eddy currents derived from the magnetic domain wall movements, and is responsible for the frequency dependence of hysteresis loops. In this paper, based on a lumped model and fractional derivative operators, we demonstrate that it is possible to replace the coupled diffusion/dynamic hysteresis in a simplest formulation using fractional operators. Such a formulation can be solved easily. Instead of solving a 1D problem of diffusion, we show here that a lumped model with appropriate fractional time derivative operator can be an exact formulation of the problem. In addition, we confirm that the model is using experimental available information, obtained by standard single sheet tester measuring bench (the tangential surface excitation field, and the cross section average induction).