PERMANENT MAGNET, MAGNETIC CORE HAVING THE MAGNET AS BIAS MAGNET, AND INDUCTANCE PARTS USING THE CORE

摘要

A permanent magnet which is a bonded magnet comprising a magnet powder and a resin in a resin content of 20 vol % or higher and has a resistivity of 0.1 OMEGA cm or more, wherein the magnet powder is a rare earth magnet powder having an intrinsic coercive force of 5 kOe or more, a Curie point Tc of 300 DEG or higher and an average particle diameter of 2.0 mu m to 50 mu m. The permanent magnet can be suitably used as a bias magnet which is arranged at a gap of a magnetic core in order to impart excellent direct current superimposing characteristics and also excellent core loss characteristics to the magnetic core. For use in a magnetic core of inductance parts which are subjected to soldering reflow treatment, a bonded magnet having a resin content of 30 % or more is used, wherein use is made of a Sm-Co magnet powder having an intrinsic coercive force of 10 kOe or more, a Curie point Tc of 500 DEG or higher and an average particle diameter of 2.5 mu m or more. This bonded magnet permits the preparation of a thin plate magnet having a thickness of 500 mu m or less for use in inductance parts of the miniature size.