Abstract: A Ni-containing plating film includes a lower plating film and an upper plating film laminated on lower plating film. The lower plating film is formed by plating with no saccharin sodium added to a plating bath, and the upper plating film is formed by plating with saccharin sodium added to a plating bath. In the upper plating film, a NiS layer exists at a position below the film surface.

Abstract: The upper magnetic pole layer and/or lower magnetic pole layer comprises a soft magnetic film having a variable region in which the chemical composition of Fe changes in the direction of thickness in at least a part thereof, and the difference of the proportions of Fe between the regions most abundant in Fe and most deficient in Fe is 4% by mass or more in the variable region. The structure of the soft magnetic film permits the saturation magnetic flux density Bs to be improved while decreasing the coercive force Hc by forming fine crystal grains, thereby enabling a thin film magnetic head excellent in high density recording to be manufactured.

Abstract: In a recordable data storage medium on which property data was recorded after having been modulated and on which data that is decodable by a cryptographic key to be generated from the property data was recorded, the property data was preferably modulated by a different method from that applied to a read-only data storage medium. Then, an optical disc drive, having no ability to distinguish the recordable data storage medium from the read-only data storage medium, cannot read the recordable data storage medium. Consequently, a greater number of drives should be equipped with the function of recognizing the type of a given data storage medium and the copyright protection function should be consolidated.

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 soft magnetic film of the present invention is a plated film composed of Co and Fe, and columnar crystals extending in the film thickness direction are provided. In the present invention, columnar crystals extending in the film thickness direction are provided so that an improvement in the surface roughness of the film surface and an improvement in the corrosion resistance can be achieved. Furthermore, the saturation magnetic flux density Bs can also be improved by making the crystal fine and eliminating the need for addition of the noble metal element. That is, according to a CoFe alloy of the present invention, both the corrosion resistance and the saturation magnetic flux density Bs can be improved, and specifically, the above-mentioned saturation magnetic flux density Bs can be increased to 2.35 T or more.

Abstract: A gap of a thin-film magnetic head is formed of NiP. The P content of the NiP gap layer is controlled to be within the range of 11 mass percent to 14 mass percent so that the gap layer is nonmagnetic.

Abstract: A lower magnetic pole layer and/or an upper magnetic pole layer are formed of a CoFe? 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 ? (the element ? 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.

Abstract: A soft magnetic film composed of an alloy represented by the formula FeNiRe is used for forming a lower core layer and/or an upper core layer. Since having a high saturated magnetic flux density, a high resistivity, superior corrosion resistance, and a small loss in a high frequency signal region, the FeNiRe alloy can be used for forming a highly reliable thin film magnetic head.

Abstract: A soft magnetic film comprising an FeCo alloy containing noble metals such as Pr and Rh. This soft magnetic film has a saturation magnetic flux density Bs of at least 2.0 and high corrosion resistance. This soft magnetic film may be included in a thin-film magnetic head. A lower magnetic pole layer or an upper magnetic pole layer of the thin-film magnetic head has a composition represented by the formula FeXCoY?Z, wherein ? is at least one element selected from the group consisting of Pd, Pt, Ru, and Ir, and wherein the ratio X/Y by mass percent of Fe to Co is in the range of 2 to 5, the ? content Z is in the range of 0.5 to 18 mass percent, and X+Y+Z=100 mass percent.

Abstract: A gap depth determining insulating layer is formed on a lower core layer. A curved face is formed on a front edge face of the gap depth determining insulating layer so as to gradually depart from an ABS surface from the bottom at the lower core layer to the top of the curved face. A back end of an upper magnetic layer can be formed on the gap depth determining insulating layer, whereby the volume of the upper magnetic layer can be increased while a gap depth is maintained at a predetermined length.

Abstract: A soft magnetic film is formed which is represented by the formula (FexNiy)aMob, in which 0.65?x?0.75 and x+y=1 are satisfied when x and y are on a mass percent ratio basis, and 0<b?5 and a+b=100 are satisfied when a and b are on a mass percent basis, and by using this soft magnetic film, a lower core layer and/or an upper core layer is formed. Accordingly, a saturated magnetic flux density of 1.6 T or more and a resistivity of 40 ??·cm or more can be obtained, and hence a thin film magnetic head having a small loss in a high frequency signal region can be provided.

Abstract: A gap layer of a thin-film magnetic head is formed of NiP. The P content of the NiP gap layer is controlled to be within the range of 11 mass percent to 14 mass percent so that the gap layer is nonmagnetic.

Abstract: A magnetic head includes an upper magnetic pole layer formed by electroplating in which the density of the impressed current is increased in stages every predetermined period of time. The upper magnetic pole layer contains at least 60 mass % of Fe. The difference between the maximum Fe content and the minimum Fe content of the upper magnetic pole layer within 0.3 ?m from the interface with the gap layer is 6 mass % or less.

Abstract: A lower pole layer and/or an upper pole layer is formed by plating a soft magnetic film represented by the formula FeXNiY?Z (wherein element ? 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 ? 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.

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 magnetic pole layer and/or an upper magnetic pole layer are formed of a CoFe? 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 ? (the element ? 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.

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 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 soft magnetic film has a composition represented by the formula FeXCoY&agr;Z wherein &agr; is at least one element selected from the group consisting of Rh, Pd, Pt, Ru, and Ir and X+Y+Z=100 mass percent. The ratio X/Y by mass percent of Fe to Co is in the range of 2 to 5, and the &agr; content Z is in the range of 0.5 to 18 mass percent. This alloy exhibits a saturation magnetic flux density of at least 2.0 T and high corrosion resistance.

Abstract: An upper shield layer includes a Ni—Fe alloy underlying film formed by sputtering deposition, and a Ni—Fe alloy plating film formed on the underlying film by electroplating. The Fe composition ratio distribution of the upper shield layer in the thickness direction ranges from 17 to 19% by weight.