Design of Permalloy-ferrite-polymer soft magnetic composites doped by ferrite nanoparticles and visualization of magnetic domains

Soft magnetic composite materials were prepared by powder metallurgy technology. The composition of the new family of the materials was based on Permalloy type of ferromagnetic particles covered by Ni_0.2Zn_0.8Fe₂O₄ nanoparticles. The spinel ferrite was prepared by electrospinning technology for achieving high-quality nanoparticles. A small amount of organic additives was included in final samples. The influence of magnetic ferrite dielectric coating on the magnetic properties of prepared composites was studied. The relatively high electrical resistivity leads to the real part of complex permeability up to 52 with stability up to high frequencies of about 1 MHz. SEM and TEM analyses were employed for composite characterization. The preparation of samples for magnetic force microscopic analysis is outlined in detail. The visualization of magnetic domain structure was done in order to understand the material behaviour of magnetic materials. (author)