Core–Shell α-Fe/FeOx Nanoparticles Synthesized by Electrical Explosion of a Wire and Ball Milling. Experience in the Development of a Micromagnetic Digital Twin

Peculiarities of the structure and magnetic properties of iron-based (α-Fe) nanoparticles synthesized by electrical explosion of a wire and subsequent ball milling are studied. Structural analysis showed that the particles consist of an α-Fe core with a nanocrystalline oxide (FeOx) shell. Based on experimental data (XRD, TEM), a micro-magnetic digital twin of a particle 50 nm in diameter is developed using a Mumax3 software, and portions of the magnetic hysteresis loops are calculated for two cases, namely, taking into account thermal fluctuations (for a temperature of 293 K) and ignoring them (for a temperature of 0 K). The effect of the nanocrystalline oxide layer on the magnetic structure of the core is found, and the general appearance of magnetic hysteresis loop is determined.