PERMEABILITY OF MICRO-STRIP PATTERNED MAGNETIC THIN-FILMS

A high permeable magnetic thin strip film is strongly required for a main pole of an ultra high density perpendicular recording head. Permeability for single- and double-layered NiFe strips of thickness less than 60 nm as a function of strip width was investigated. The permeability reduced monotonically with decreasing the strip width for single-layered strips and, however, exhibited a large peak value at a certain strip width for double-layered strips with a Ti interlayer. By adjusting the Ti interlayer thickness, a permeability over 1500 could be obtained even for narrow strips of 2 mu m width.