Dynamic magnetic information storage or retrieval – Head – Hall effect
Patent
1993-10-15
1995-11-07
Levy, Stuart S.
Dynamic magnetic information storage or retrieval
Head
Hall effect
32420721, 324252, 338 32R, G11B 539
Patent
active
054651859
ABSTRACT:
A spin valve magnetoresistive (MR) sensor uses a multifilm laminated pinned ferromagnetic layer in place of the conventional single-layer pinned layer. The laminated pinned layer has at least two ferromagnetic films separated by an antiferromagnetically coupling film. By appropriate selection of the thickness of the antiferromagnetically coupling film, depending on the material combination selected for the ferromagnetic and antiferromagnetically coupling films, the ferromagnetic films become antiferromagnetically coupled. In the preferred embodiment, the pinned layer is formed of two films of nickel-iron (Ni--Fe) separated by a ruthenium (Ru) film having a thickness less than approximately 10 .ANG.. Since the pinned ferromagnetic films have their magnetic moments aligned antiparallel with one another, the two moments can be made to essentially cancel one another by making the two ferromagnetic films of substantially the same thickness. As a result, there is essentially no dipole field to adversely affect the free ferromagnetic layer, which improves the sensitivity of the sensor and allows higher recording density to be achieved in a magnetic recording data storage system.
REFERENCES:
patent: 4949039 (1990-08-01), Grunberg
patent: 5134533 (1992-07-01), Friedrich et al.
patent: 5159513 (1992-10-01), Dieny et al.
patent: 5206590 (1993-04-01), Dieny et al.
patent: 5287238 (1994-02-01), Baumgart et al.
patent: 5301079 (1994-04-01), Cain et al.
patent: 5304975 (1994-04-01), Saito et al.
patent: 5313186 (1994-05-01), Schuhl et al.
patent: 5315468 (1994-05-01), Lin et al.
patent: 5341261 (1994-08-01), Dieny et al.
Binasch et al., "Enhanced Magnetoresistance in Layered Magnetic Structures with Antiferromagnetic Interlayer Exchange", Physical Review B, vol. 39, No. 7, Mar. 1, 1989, pp. 4828-4830.
Dieny et al., "Change in Conductance is the Fundamental Measure of Spin-Valve Magnetoresistance", Applied Phsyics Letters, vol. 61, No. 17, Oct. 26, 1992, pp. 2111-2113.
Dieny, "Quantitative Interpretation of Giant Magnetoresistance Properties of Permalloy-based Spin-Valve Structures", Europhysics Letters, vol. 17, No. 3, Jan. 14, 1992, pp. 261-267.
Dieny, "Classical Theory of Giant Magnetoresistance in Spin-Valve Multilayers: Influence of Thickness, Number of Periods, Bulk and Interfacial Spin-dependent Scattering", Journal of Physics: Condensed Matter, vol. 4, 1992, pp. 8009-8020.
Dieny et al., "Giant Magnetoresistance in Soft Ferromagnetic Multilayers", Physical Review B, vol. 43, No. 1, Jan. 1, 1991, pp. 1297-1300.
Levy, "Giant Magnetoresistance in Magnetic Layered and Granular Materials", Science, vol. 256, May 15, 1992, pp. 972-973.
Parkin et al., "Giant Magnetoresistance in Antiferromagnetic Co/Cu Multilayers", Applied Physics Letters, vol. 58, No. 23, Jun. 10, 1991, pp. 2710-2712.
Parkin et al., "Spin Engineering: Direct Determination of the Ruderman-Kittel-Kasuya-Yosida Far-field Range Function in Ruthenium", Physical Review B, vol. 44, No. 13, Oct. 1, 1991, pp. 7131-7134.
Parkin et al., "Oscillations in Exchange Coupling and Magnetoresistance in Metallic Superlattice Structures: Co/Ru, Co/Cr, and Fe/Cr", Physical Review Letters, vol. 64, No. 19, May 7, 1990, pp. 2304-2307.
Parkin et al., "Oscillatory Magnetic Exchange Coupling Through Thin Copper Layers", Physical Review Letters, vol. 66, No. 16, Apr. 22, 1991, pp. 2152-2155.
Parkin, "Systematic Variation of the Strength and Oscillation Period of Indirect Magnetic Exchange Coupling through the 3d, 4d, and 5d Transition Metals", Physical Review Letters, vol. 67, No. 25, Dec. 16, 1991, pp. 3598-3601.
Parkin, "Giant Magnetoresistance and Oscillatory Interlayer Exchange Coupling in Copper Based Multilayers", Materials Research Society Symposium Proceedings, vol. 231, 1992, pp. 211-216.
Pennisi, "Magnetic Advantage: Magnetic Fields Make New Thin Films Better Conductors", Science News, vol. 142, Aug. 29, 1992, pp. 140-142.
Heim David E.
Parkin Stuart S. P.
Berthold Thomas R.
International Business Machines - Corporation
Letscher George J.
Levy Stuart S.
LandOfFree
Magnetoresistive spin valve sensor with improved pinned ferromag does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Magnetoresistive spin valve sensor with improved pinned ferromag, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnetoresistive spin valve sensor with improved pinned ferromag will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-200511