Patent ID: 7808748
Filing Date: 2010-10-05
Classification: B82Y,G01R,G11B,H01L

Abstract:
1. A magnetoresistive element comprising: a nonmagnetic layer having a first surface and a second surface that face toward opposite directions; a pinned layer disposed adjacent to the first surface of the nonmagnetic layer, a direction of magnetization in the pinned layer being fixed, and a free layer disposed adjacent to the second surface of the nonmagnetic layer, a direction of magnetization in the free layer changing in response to an external magnetic field, wherein a current for detecting magnetic signals is fed in a direction intersecting a plane of each of the foregoing layers, and wherein: of the pinned layer and the free layer, at least the pinned layer includes an underlying magnetic layer made of a magnetic alloy layer having a body-centered cubic structure, and a Heusler alloy layer formed on the underlying magnetic layer; the Heusler alloy layer is made of a CoMnSi alloy having an Mn content higher than 25 atomic percent and lower than or equal to 40 atomic percent, and the Heusler alloy layer contains a principal component having a B2 structure in which Co atoms are placed at body-centered positions of unit cells and Mn atoms or Si atoms are randomly placed at vertexes of the unit cells; the Heusler alloy layer that the pinned layer includes is disposed between the underlying magnetic layer that the pinned layer includes and the nonmagnetic layer; the pinned layer further includes a middle magnetic layer disposed between the Heusler alloy layer that the pinned layer includes and the nonmagnetic layer; and the middle magnetic layer contains ‘z’ atomic percent Fe and (100−z) atomic percent Co, where z is within a range of 30 to 100 inclusive.