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

Published

December 1, 1997

Author(s)

William F. Egelhoff Jr., P J. Chen, Cedric J. Powell, Mark D. Stiles, Robert McMichael, J Judy, K Takano, A. E. Berkowitz

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 leyers, 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 create a surface which scatters electrons more specularly. Using this technique, bottom spin valves and symmetric spin valves with GMR values of 19.0% and 24.8% respectively, have been produced. These are the largest valves ever reported for such structures.

Citation

Applied Physics

Volume

82

Issue

No. 12

Pub Type

Journals

Keywords

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

Citation

Egelhoff Jr., W. , Chen, P. , Powell, C. , Stiles, M. , McMichael, R. , Judy, J. , Takano, K. and Berkowitz, A. (1997), Oxygen as a Surfactant in the Growth of Giant Magnetoresistance Spin Valves, Applied Physics (Accessed October 14, 2025)