Application of nanocrystalline soft magnetic Fe–M–B (M=Zr, Nb) alloys to choke coils

Abstract

We have developed a choke coil made of new nanocrystalline soft magnetic Fe–M–B (M=Zr, Nb) alloys (“NANOPERM™ ” material) which exhibit high saturation magnetic induction (Bs), above 1.5 T, excellent soft magnetic properties and zero magnetostriction. A choke coil made of NANOPERM™ material exhibits good dc bias characteristics of inductance because of the high Bs. Furthermore, the choke coil made from NANOPERM™ material showed 1/3rd the temperature rise shown by a core made from Fe–Si–B amorphous alloy. The low core loss and high Bs of NANOPERM™ material allow the reduction of the core size. It is concluded that NANOPERM™ is suitable as a core material for choke coils.