Dynamic magnetic information storage or retrieval – Head – Hall effect
Patent
1997-05-13
1998-10-20
Renner, Craig A.
Dynamic magnetic information storage or retrieval
Head
Hall effect
G11B 539
Patent
active
058255958
ABSTRACT:
A read sensor includes first and second substantially planar magnetoresistive spin valves, parallel to each other. Each spin valve includes a pair of ferromagnetic layers. Between the spin valves lies a bias conductor, separated from each spin valve by respective insulating layers. In each spin valve, the outer ferromagnetic layer is a current-induced ferromagnetic pinned layer whose magnetization direction is pinned by a pinning field supplied by a bias current flowing in the bias conductor. Sense currents are directed through the spin valves in a direction substantially perpendicular to the magnetization directions of the current-induced ferromagnetic pinned layers. The magnetization orientations of the ferromagnetic layers are established by a combined field provided by the sense and bias currents. When the read sensor detects an external magnetic field, each spin valve exhibits a voltage drop. With external magnetic fields occurring in a predetermined range, one spin valve's voltage drop is directly proportional to the magnetic flux transitions, and the other is inversely proportional to the magnetic flux transitions. Thus, if the spin valves' output signals are subtracted, the desired signal is amplified while common mode noise is canceled out. Advantageously, no antiferromagnetic layers are needed to pin the magnetization directions of the current-induced ferromagnetic pinned layers. Thus, problems with antiferromagnetic layers, such as blocking temperatures, are avoided.
REFERENCES:
patent: 4103315 (1978-07-01), Hempstead et al.
patent: 4809109 (1989-02-01), Howard et al.
patent: 5027243 (1991-06-01), Gill et al.
patent: 5159513 (1992-10-01), Dieny et al.
patent: 5193038 (1993-03-01), Smith
patent: 5206590 (1993-04-01), Dieny et al.
patent: 5262914 (1993-11-01), Chen et al.
patent: 5264980 (1993-11-01), Mowry et al.
patent: 5287238 (1994-02-01), Baumgart et al.
patent: 5301079 (1994-04-01), Cain et al.
patent: 5341261 (1994-08-01), Dieny et al.
patent: 5471358 (1995-11-01), Tadokoro et al.
patent: 5508866 (1996-04-01), Gill et al.
patent: 5528440 (1996-06-01), Fontana et al.
patent: 5557491 (1996-09-01), Gill et al.
patent: 5561368 (1996-10-01), Dovek et al.
patent: 5576915 (1996-11-01), Akiyama et al.
patent: 5627703 (1997-05-01), Smith
patent: 5701222 (1997-12-01), Gill et al.
U.S. Patent Application No. 08/606,625, "System for Resetting Sensor Magnetization in a Spin Valve Magnetoresistive Sensor", filed Feb. 26, 1996, Speriosu et al.
IBM Technical Disclosure Bulletin, vol. 30, No. 8, pp. 461-464 Jan. 1988, "Close Proximity Coupled Differential Magneto-Resistive Read Head Structure", A. W. Vinal.
J. Appl. Phys., vol. 76, No. 9, Nov. 1, 1994, "Distribution of Blocking Temperature in Bilayered Ni.sub.81 Fe.sub.19 /NiO Films", S. Soeya et al., pp. 5356-5360.
J. Appl. Phys., vol. 79, No. 8, Apr. 15, 1996, "Exchange Coupling of Sputter Deposited NiCo-O/NiFe Thin Films", M. Tan et al., pp. 5012-5014.
IEEE Transactions on Magnetics, vol. 32, No. 1, Jan. 1996, "Spin-Valve Heads Utilizing Antiferromagnetic NiO Layers", Y. Hamakawa et al., pp. 149-155.
Appl. Phys. Lett., Dec. 2, 1996, "NiMn-pinned Spin Valves with High Pinning Field Made by Ion Beam Sputtering", S. Mao et al., pp. 3593-3595.
Journal of Magnetism and Magnetic Materials, 1994, "Giant Magnetoresistance in Spin-Valve Multilayers", B. Dieny, pp. 335-359.
IEEE Transations on Magnetics, vol. 28, No. 5. Sep. 1992, "Giant Magnetoresistance: A Primer", R. L. White, pp. 2481-2487.
International Business Machines - Corporation
Renner Craig A.
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