A Nonlinear Theoretical Model of Magnetization and Magnetostriction for Ferromagnetic Materials under Applied Stress and Magnetic Fields

A thermodynamic and micro-statistical model is proposed to explain the magnetization and magnetostriction mechanisms for isotropic ferromagnetic materials. Here a nonlinear magnetostrictive expression enhances the characterization of the nonlinear magnetic-mechanical effect, and the Brillouin function makes it possible to describe the relationship between the equivalent field and magnetization for various types of materials. Through detailed comparisons with the recent models of Wu et al. Appl. Phys. Lett. 115 (2019) 162406 and Daniel Eur. Phys. J.: Appl. Phys. 83 (2018) 30904, it is confirmed that the proposed model can provide greater physical insight and a more accurate description of the complex magnetostriction and magnetization behaviors, especially the complex nonlinearity of stress effects.