The data of the paper "Synergistic enhancement of permeability and reduction of core loss in FeNi50@SiO₂ soft magnetic composites via particle size tailored coating"

The particle size distribution (PSD) of the raw FeNi50 powder was analyzed using a laser particle size analyzer (Malvern Instruments, Mastersizer 3000). The powder morphology and elemental distribution of FeNi50 powders before and after SiO2 coating, as well as the cross-section morphology of the toroidal samples, were obtained using scanning electron microscopy (SEM, TESCAN CLARA GMH) coupled with energy dispersive X-ray spectroscopy (EDS). The composition of the composite powders, both before and after annealing at 500°C, was analyzed using X-ray diffraction (XRD, Bruker D8 Advance) within a 2θ range of 20-80°, Fourier transform infrared spectroscopy (FTIR, Thermo Fisher, Nicolet iS5), X-ray photoelectron spectroscopy (XPS, SHIMADZU CORPORATION, AXIS SUPRA+), and thermogravimetric analysis (TGA, STA 449 F3). The composite powder was sectioned using the focused ion beam-scanning electron microscope (FIB-SEM, Carl Zeiss (Crossbeam 350) and FEI (Helios 5 CX)) and then the morphology, thickness, and elemental distribution of the coating layer were examined using high resolution scanning transmission electron microscopy (TEM, JEM-F200) equipped with EDS. The static magnetic properties (Hysteresis loop) of the SMCs powders were analyzed using a vibrating sample magnetometer (VSM, Versalab, Quantum Design) within a maximum magnetic field of 2388 kA/m (1 Oe ≈ 79.6 A/m). The AC magnetic properties (Electrical inductance and core loss) of the toroidal samples were characterized using an LCR meter (Tonghui, TH2838) and a B-H analyzer (IWATSU, SY-8218). The flowability of the powders and the density of the toroidal samples were measured using a Hall flowmeter and a densitometer (METTLER TOLEDO), respectively.