| US 7,599,157 B2 | ||
| Current-perpendicular-to-the-plane (CPP) magnetoresistive sensor with high-resistivity amorphous ferromagnetic layers | ||
| Matthew J. Carey, San Jose, Calif. (US); Jeffrey R. Childress, San Jose, Calif. (US); and Stefan Maat, San Jose, Calif. (US) | ||
| Assigned to Hitachi Global Storage Technologies Netherlands B.V., Amsterdam (Netherlands) | ||
| Filed on Feb. 16, 2006, as Appl. No. 11/356,546. | ||
| Prior Publication US 2007/0188937 A1, Aug. 16, 2007 | ||
| This patent is subject to a terminal disclaimer. | ||
| Int. Cl. G11B 5/39 (2006.01) | ||
| U.S. Cl. 360—324.11 [360/324.12] | 18 Claims |
| 1. A current-perpendicular-to-the-plane spin-valve (CPP-SV) magnetoresistive sensor capable of sensing external magnetic fields
when a sense current is applied perpendicular to the planes of the layers in the sensor, the sensor comprising:
a substrate;
a pinned ferromagnetic layer having an in-plane magnetization direction;
an antiparallel-coupled free ferromagnetic layer having an in-plane magnetization direction substantially free to rotate in
the presence of an external magnetic field and comprising a first free ferromagnetic layer, a second free ferromagnetic layer
and an antiparallel coupling (APC) layer between the first and second free layers; and
an electrically conductive spacer layer between the first free ferromagnetic layer and the pinned ferromagnetic layer with
the first free layer being between the spacer layer and the APC layer of said free layer; wherein at least one of the first
free layer and the pinned layer comprises an amorphous ferromagnetic alloy comprising a nonmagnetic element X, wherein X is
selected from the group consisting of B, Tb, Si, Ge, Nb and Mg, and at least one of Co, Ni and Fe.
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