| US 7,616,410 B2 | ||
| Magnetic detecting element having free layer formed of NiFe alloy and method of manufacturing the same | ||
| Masahiko Ishizone, Niigata-ken (Japan); Yosuke Ide, Niigata-ken (Japan); Masamichi Saito, Niigata-ken (Japan); and Naoya Hasegawa, Niigata-ken (Japan) | ||
| Assigned to TDK Corporation, Tokyo (Japan) | ||
| Filed on Feb. 21, 2006, as Appl. No. 11/358,825. | ||
| Claims priority of application No. 2005-057813 (JP), filed on Mar. 02, 2005. | ||
| Prior Publication US 2006/0198060 A1, Sep. 07, 2006 | ||
| Int. Cl. G11B 5/39 (2006.01) | ||
| U.S. Cl. 360—324.12 [29/603.14] | 14 Claims |
| 1. A magnetic detecting element comprising:
a pinned magnetic layer whose magnetization direction is fixed; and
a free magnetic layer which is formed on the pinned magnetic layer with a non-magnetic layer interposed therebetween and whose
magnetization direction varies in accordance with an external magnetic field,
wherein the free magnetic layer is formed of NiFeX alloy layer only or NiFeX alloy layer and a diffusion preventive layer
formed of CoFe (an element X is composed of at least one element selected from Cu, Sc, Ti, Zn, Zr, Hf, Au, Ag, Mn, and Al),
an average composition ratio of the element X is in the range of 5 to 20 atomic percent, and
regions where the composition ratio of the element X increases from the lower surface toward the upper surface of the NiFeX
alloy layer, and regions where the composition ratio of the element X decreases from the lower surface toward the upper surface
of the NiFeX alloy layer are alternately formed.
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