Structure, magnetic and microwave properties of FeNi nanoparticles obtained by electric explosion of wire

Magnetic nanoparticles (MNPs) of FeNi were prepared by the electric explosion of wire aiming to obtain a large batch of magnetic nanomaterial with enhanced effective magnetization. X-ray diffraction, transmission, scanning electron microscopy, low temperature nitrogen adsorption, magnetization and microwave absorption measurements were used for full characterization. The shape of the MNPs with weight averaged mean diameter of 69 ± 8 nm, was very close to being spherical. The saturation magnetization of about 140 emu/g up for 300 K was established. The room temperature microwave signal was very complex due to sizable zero field absorption and various contributions. We obtain reasonable agreement between structural magnetic and microwave techniques by taking into account the presence of so-called "twin" structure in the MNPs.