Abstract: A high-specific-resistance layer is formed on a soft magnetic layer of an upper core layer in a thin-film magnetic head. The high-specific-resistance layer has a specific resistance which is higher than the specific resistance of the softer magnetic layer. This high-specific-resistance layer can reduce eddy current loss which is generated as the recording frequency increases. The thin-film magnetic head is suitable for high recording frequencies.

Abstract: A lower pole layer and/or an upper pole layer is formed by plating a NiFe alloy having a Fe composition ratio of 76% by mass to 90% by mass, or having an average crystal grain diameter of 130 Å to 175 Å and a Fe composition ratio of 70% by mass to 90% by mass. As a result, the saturation magnetic flux density can be increased to 1.9 t or more, and a thin film magnetic head excellent for a higher recording density can be manufactured.

Abstract: A lower magnetic pole layer and/or an upper magnetic pole layer are formed of a CoFe&agr; alloy in which the component ratio X of Co is 8 to 48 mass %, the component ratio Y of Fe is 50 to 90 mass %, the component ratio Z of the element &agr; (the element &agr; is at least one of Ni and Cr) is 2 to 20 mass %, and the equation X+Y+Z=100 mass % is satisfied. Consequently, the saturated magnetic flux density can be 2.0 T or more, and a thin-film magnetic head have a higher recording density can be manufactured.

Abstract: A soft magnetic film is formed of a CoFe alloy having an Fe content in the range of 68 to 80 mass %, thereby having a saturation magnetic flux density of 2.0 T or more. The center lain average roughness of the film surface is 9 nm or less. The soft magnetic film can achieve a corrosive resistant magnetic head with a high recording density.

Abstract: A lower pole layer and/or an upper pole layer is formed by plating a soft magnetic film represented by the formula FeXNiY&agr;Z (wherein element &agr; is at least one of Tc, Ru, Rh, Pd, Re, Os, Ir and Pt), wherein the composition ratio X of Fe is 65% by mass to 74% by mass, the composition ratio Y of Ni 25% by mass to 34% by mass, the composition ratio Z of the element &agr; is 1% by mass to 7% by mass, and X+Y+Z=100% by mass. Therefore, a thin film magnetic head adaptable to a higher recording density and having excellent corrosion resistance can be manufactured.