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



P J. Chen, Cedric J. Powell, Mark D. Stiles, Robert McMichael, J Judy, K Takano, A Berkowitz


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.
Journal of Applied Physics


Giant Magnetoresistance(GMR), magnetic layers, spin valves, surfactant


Chen, P. , Powell, C. , Stiles, M. , McMichael, R. , Judy, J. , Takano, K. and Berkowitz, A. (1998), Oxygen as a Surfactant in the Growth of Giant Magnetoresistance Spin Valves, Journal of Applied Physics (Accessed November 28, 2023)
Created December 31, 1997, Updated October 12, 2021