Dynamic magnetic information storage or retrieval – Head – Hall effect
Patent
1998-05-29
2000-02-08
Klimowicz, William J.
Dynamic magnetic information storage or retrieval
Head
Hall effect
G11B 539
Patent
active
060233958
ABSTRACT:
A magnetic tunnel junction (MTJ) magnetoresistive (MR) read head has one fixed ferromagnetic layer and one sensing ferromagnetic layer on opposite sides of the tunnel barrier layer, and with a biasing ferromagnetic layer in the MTJ stack of layers that is magnetostatically coupled with the sensing ferromagnetic layer to provide either longitudinal bias or transverse bias or a combination of longitudinal and transverse bias fields to the sensing ferromagnetic layer. The magnetic tunnel junction in the MTJ MR head is formed on an electrical lead on a substrate and is made up of a stack of layers. The layers in the stack are an antiferromagnetic layer, a fixed ferromagnetic layer exchange biased with the antiferromagnetic layer so that its magnetic moment cannot rotate in the presence of an applied magnetic field, an insulating tunnel barrier layer in contact with the fixed ferromagnetic layer, a sensing ferromagnetic layer in contact with the tunnel barrier layer and whose magnetic moment is free to rotate in the presence of an applied magnetic field, a biasing ferromagnetic layer that has its magnetic moment aligned generally within the plane of the device and a nonmagnetic electrically conductive spacer layer separating the biasing ferromagnetic layer from the other layers in the stack. The self field or demagnetizing field from the biasing ferromagnetic layer magnetostatically couples with the edges of the sensing ferromagnetic layer to stabilize its magnetic moment, and, to linearize the output of the device. The electrically conductive spacer layer prevents direct ferromagnetic coupling between the biasing ferromagnetic layer and the other layers in the stack and allows sense current to flow perpendicularly through the layers in the MTJ stack.
REFERENCES:
patent: 3623038 (1971-11-01), Franklin et al.
patent: 5018037 (1991-05-01), Krounbi et al.
patent: 5390061 (1995-02-01), Nakatani et al.
patent: 5416353 (1995-05-01), Kamiguchi et al.
patent: 5432734 (1995-07-01), Kawano et al.
patent: 5465185 (1995-11-01), Heim et al.
patent: 5528440 (1996-06-01), Fontana et al.
patent: 5695864 (1997-12-01), Slonczewski
patent: 5726837 (1998-03-01), Nakatani et al.
patent: 5729410 (1998-03-01), Fontana et al.
patent: 5898547 (1999-04-01), Fontana, Jr. et al.
M. Julliere, "Tunneling Between Ferromagnetic Films", Physics Letters, vol. 54A, No. 3, Sep. 8, 1975, pp. 225-226.
K. Matsuyama et al., "Fabrication of Microstructured Magnetic Tunneling Valve Junction", IEEE Transactions on Magnetics, vol. 31, No. 6, Nov. 1995, pp. 3176-3178.
J. S. Moodera et al., "Ferromagnetic-insulator-ferromagnetic Tunneling: Spin-dependent Tunneling and Large Magnetoresistance in Trilayer Junctions", Symposium on Spin Tunneling and Injection Phenomena, Journal of Applied Physics, vol. 79, No. 8, Apr. 15, 1996, pp. 4724-4729.
Dill Frederick Hayes
Fontana, Jr. Robert Edward
Lin Tsann
Papworth Parkin Stuart Stephen
Tsang Ching Hwa
Berthold Thomas R.
International Business Machines - Corporation
Klimowicz William J.
LandOfFree
Magnetic tunnel junction magnetoresistive sensor with in-stack b does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Magnetic tunnel junction magnetoresistive sensor with in-stack b, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnetic tunnel junction magnetoresistive sensor with in-stack b will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1685755