Soft magnetic film having saturation magnetic flux density Bs of at least 2.0 T and magnetic head including the same
AssigneeAlps Electric Co., Ltd.
InventorsMitsuhiro Gotoh, Yoshihiro Kanada
Life of this patent
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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 FeXCoYαZ, wherein α 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 α content Z is in the range of 0.5 to 18 mass percent, and X+Y+Z=100 mass percent.
Claims18
A soft magnetic film having a composition represented by the formula FeXCoYαZβZ and formed by plating, wherein α is at least one element selected from the group consisting of Pd, Pt, Ru, and Ir, β is at least one of Ni and Cr,band wherein the ratio X/Y by mass percent of Fe to Co is in the range of 2 to 5, the α content Z is in the range of 0.5 to 18 mass percent, the β content V is in the range of 0.5 to 5 mass percent, and V+X+Y+Z=100 mass percent.
A soft magnetic film having a composition represented by the formula FeXCoYRhW and formed by plating, wherein the Fe content X is 57 mass percent or more, the Co content Y is 20 mass percent or more, the Rh content W is 9 mass percent or more, and X+Y+W=100 mass percent.
A soft magnetic film having a composition represented by the formula FeXCoYRhW and formed by plating, wherein the Fe content X is 57 mass percent or more, the Co content Y is 20 mass percent or more, the Rh content W is in the range 9 to 10 mass percent, and X+Y+W=100 mass percent, wherein the ratio X/Y by mass percent of Fe to Co is in the range of 2.030 to 2.704.
A soft magnetic film having a composition represented by the formula FeXCoYRhWβV and formed by plating, wherein the Fe content X is 57 mass percent or more, the Co content Y is 20 mass percent or more, the Rh content W is in the range 1.7 to 20 mass percent, β is at least one of Ni and Cr, and the β content V is in the range of 0.5 to 5 mass percent, and X+Y+W+V=100 mass percent.
A thin-film magnetic head comprising a magnetic lower core layer, an upper core layer formed on the magnetic lower core layer with a magnetic gap provided therebetween, a coil layer for applying a recording magnetic field to the lower core layer and the upper core layer, wherein at least one of the lower core layer and the upper core layer comprises a soft magnetic film having a composition represented by the formula FeXCoYRhW and formed by plating, wherein the Fe content X is 57 mass percent or more, the Co content Y is 20 mass percent or more, the Rh content W is in the range of 7.5 to 20 mass percent, and X+Y+W=100 mass percent.
A thin-film magnetic head comprising:
- a lower core layer;
- an upper core layer;
- and
- a magnetic pole unit between the lower core layer and the upper core layer, a width of the magnetic pole unit being shorter than that of the lower core layer and the upper core layer in a track width direction,
- the magnetic pole unit comprising:
- a lower magnetic pole layer in contact with the lower core layer;
- an upper magnetic pole layer in contact with the upper core layer;
- and a gap layer lying between the lower magnetic pole layer and the upper magnetic pole layer, or comprising:
- an upper magnetic pole layer in contact with the upper core layer and a gap layer lying between the upper magnetic pole layer and the lower core layer,
- wherein at least one of the upper magnetic pole layer and the lower magnetic pole layer comprises a soft magnetic film having a composition represented by the formula FeXCoYRhw and formed by plating, wherein the Fe content X is 57 mass percent or more, the Co content Y is 20 mass percent or more, the Rh content W is 9 mass percent or more, and X+Y+W=100 mass percent.
Dependencies are inferred from the claim text.