The replacement spring magnet and its manufacturing method

PROBLEM TO BE SOLVED : To obtain a thin film magnet having a high max. energy product by laminating a soft magnetic layer having specified magnetization value on a hard magnetic layer contg. specified amt. of rare earth element(s), B and Fe or Fe partly substituted with Co and inevitable impurities. SOLUTION : Laminating an S layer (soft magnetic layer having a magnetization of 1.3T or more) on an H layer (hard magnetic layer contg. R (at least one of rare earth elements, incl. Y) 10-20at%, B 5-20at%, TM (Fe or Fe partly substituted with Co) and inevitable impurities) produces a thin film magnet. The S and H layers are pref. alternately laminated to form a multilayer film pref. having at the outermost surface an M layer (composed of at least one of Cr, Ti, W, Ta, FeMn, NiMn, Nip, Fed, Cod, Co-Pt and Fe-Pt, thereby suppressing oxidation of the S and H layers.