Intergranular insulated Fe/SiO2 soft magnetic composite for decreased core loss

• An intergranular insulated model was designed for soft magnetic composite.
• Fe/SiO2 core–shell particles and Fe/SiO2 composite core were prepared.
• Fe/SiO2 particles and Fe/SiO2 composite core showed good soft magnetic properties.
• Fe/SiO2 had lower core loss, better frequency stability and higher Q than Fe core.
• The insulating layer between ferromagnetic particles can reduce core loss.

An intergranular insulated Fe/SiO2 soft magnetic composite has been designed to reduce the core loss and improve the magnetic properties of cores by a modified Stöber method combined with the spark plasma sintering. Most of conductive Fe particles could be coated by insulated SiO2 using the modified Stöber method. In the spark plasma sintering, the high compact and intergranular insulated cores were obtained quickly. The Fe/SiO2 composite core displayed much higher electrical resistivity, lower core loss, better frequency stability of permeability and higher quality factor than that of the raw Fe core without insulated SiO2 layers. The model introduced here provides a promising method to reduce the core loss and improve the magnetic properties for soft magnetic composite materials, which can reach larger energy conversion efficiency for electric–magnetic switching device.

Figure optionsDownload as PowerPoint slide