A magnetic cell includes a first magnetically fixed part including a laminated structure where a first ferromagnetic layer, a nonmagnetic layer and a second ferromagnetic layer are laminated, a second magnetically fixed part including a third ferromagnetic layer, a fourth ferromagnetic layer provided between the first and the second magnetically fixed parts, a first intermediate layer provided between the first magnetically fixed part and the fourth ferromagnetic layer, and a second intermediate layer provided between the second magnetically fixed part and the fourth ferromagnetic layer, a direction of magnetization of the fourth ferromagnetic layer being determined under an influence of spin-polarized electrons upon the fourth ferromagnetic layer by passing a current between the first and the second magnetically fixed parts.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation application of U.S. application Ser. No. 10/721,549, filed on Nov. 26, 2003, now U.S. Pat. No. 6,956,766 and is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2002-342447, filed on Nov. 26, 2002; the entire contents of which are incorporated herein by reference.
A magnetic recording element according to an example of the present invention includes a magnetic free layer whose magnetization is variable in accordance with a current direction passing through a film and whose direction of easy axis of magnetization is a direction perpendicular to a film plane, a magnetic pinned layer whose magnetization is fixed to a direction perpendicular to the film plane, and a non-magnetic barrier layer between the magnetic free layer and the magnetic pinned layer. In the magnetic free layer, a relation between a saturated magnetization Ms (emu/cc) and an anisotropy field Han (Oe) satisfies Han>12.57 Ms, and Han<1.2 E7 Ms.sup.-1+12.57 Ms.
An anti-parallel pinned sensor is provided with a spacer that increases the anti-parallel coupling strength of the sensor. The anti-parallel pinned sensor is a GMR or TMR sensor having a pure ruthenium or ruthenium alloy spacer. The thickness of the spacer is less than 0.8 nm, preferably between 0.1 and 0.6 nm. The spacer is also annealed in a magnetic field that is 1.5 Tesla or higher, and preferably greater than 5 Tesla. This design yields unexpected results by more than tripling the pinning field over that of typical AP-pinned GMR and TMR sensors that utilize ruthenium spacers which are 0.8 nm thick and annealed in a relatively low magnetic field of approximately 1.3 Tesla.
