Preparation of low-loss amorphous soft magnetic powder cores by joint coating of resin and ZnO nanoparticles

Low loss FeSiBCr soft magnetic powder cores were prepared by the joint coating of ZnO nanoparticles and epoxy resin. In this study, the content of ZnO nanoparticles and epoxy resin is regulated to find the best proportion of insulating coating. Scanning electron microscope exhibits that the surface of amorphous magnetic powders was covered with ZnO nanoparticles, and element distribution analysis also shows that ZnO nanoparticles are well coated on the surface of magnetic powder. The loss of soft magnetic composite materials were measured by B–H analyzer. The results show that the optimum mass ratio of ZnO nanoparticles to resin is 1:2, and FeSiBCr amorphous soft magnetic powder cores show the lowest loss of 209.4 mW/cm 3 ( f  = 1000 kHz, B m  = 20 mT).