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Publication Citation: Oxygen as a Surfactant in the Growth of Giant Magnetoresistance Spin Valves

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Author(s): P J. Chen; Cedric J. Powell; Mark D. Stiles; Robert D. McMichael; J Judy; K Takano; A Berkowitz;
Title: Oxygen as a Surfactant in the Growth of Giant Magnetoresistance Spin Valves
Published: January 01, 1998
Abstract: We have found a novel method for increasing the giant magnetoresistance (GMR) of Co/Cu spin valves with the use of oxygen. Surprisingly, spin valves with the largest GMR are not produced in the best vacuum. Introducing 5x10-9 Torr (7x10-7 Pa) into our ultrahigh vacuum deposition chamber during spin-valve growth increases the GMR, decreases the ferromagnetic coupling between magnetic layers, and decreases the sheet resistance of the spin valves. It appears that the oxygen may act as a surfactant during film growth to suppress defects and to crate a surface which scatters electrons morespecularly. Using this technique, bottom spin valves and symmetric spin valves with GMR values of 19% and 24.8%, respectively, have been produced. These are the largest values ever reported for such structures.
Citation: Journal of Applied Physics
Volume: 82
Issue: 12
Pages: pp. 6142 - 6151
Keywords: Giant Magnetoresistance(GMR);magnetic layers;spin valves;surfactant
Research Areas: Nanomagnetics