Magnetic microstructure in the as suction cast Fe ₆₉B ₂₀Nb ₂Hf ₂Si ₂Y ₅ alloy was revealed by combined Lorentz-TEM and LM-STEM DPC analysis. The thin foil of the alloy was found to be composed primarily of the amorphous phase with few dendritic structures. Magnetic domains were found large in the µm range with an average domain wall width of 52 nm. The magnetic domain boundaries are easily mobile, what was confirmed by in situ applied magnetic field. The LM-STEM DPC complements the Lorentz-TEM analysis by providing details on the intensity and spatial distribution of the magnetization vector within the domains.

Magnetic hysteresis occurs in most electrical engineering devices once soft ferromagnetic materials are exposed to relatively high temperatures. According to several scientific studies, magnetic properties are strongly influenced by temperature. The development of models that can accurately describe the thermal effect on ferromagnetic materials is still an issue that inspires researchers. In this paper, the effect of temperature on magnetic hysteresis for ferromagnetic materials is investigated using a self-developed numerical method based on the Preisach distribution function identification. It employs a parameter depending on both temperature and the Curie temperature. This approach is of the macroscopic phenomenological type, where the variation of the magnetization (in direct connection with the Preisach triangle) is related to the observed macroscopic hysteretic behavior. The isotropic character of the material medium is predominant. The technique relies on a few experimental data extracted from the first magnetization curve provided by metallurgists. The ultimate goal is to provide a simple and robust magnetic behavior modeling tool for designers of electrical devices. Temperature is introduced at the stage of identifying the distribution function of the Preisach model. This method is validated by the agreement between the experimental data and the simulation results. The developed method is very accurate and efficient in modeling the hysteresis of ferromagnetic materials in engineering particularly for systems with ferromagnetic components and electromagnetic-thermal coupling.