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 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.