Fe-based nanocrystalline alloy powder cores with excellent high frequency magnetic properties

Abstract

Toroidal shape FeSiBNbCu nanocrystalline alloy powder cores were prepared by compaction at room temperature after creating Cu-oxide layer as an insulator on the surface of FeSiBNbCu nanocrystalline alloy powder. The characteristics of the Cu-oxide layer and its effect on the high frequency magnetic properties of the compacted cores were investigated. A Cu-oxide layer was successively synthesized by electroless plating of Cu on the FeSiBNbCu nanocrystalline alloy powder and subsequent thermal oxidation. FeSiBNbCu nanocrystalline alloy powder core prepared from the powder having Cu-oxide layer exhibits a high value of quality factor and a stable permeability up to high frequency range over 10 MHz. The core loss could be reduced remarkably and the dc-bias property could be improved significantly by synthesizing Cu-oxide layer on the FeSiBNbCu nanocrystalline alloy powder. Effective insulation by Cu-oxide layer between the FeSiBNbCu nanocrystalline alloy powder could be attributed to the improvement in high-frequency properties of the FeSiBNbCu nanocrystalline alloy powder cores (C) 2008 American Institute of Physics.