Highly Deleterious Role of Small Amounts of Carbon on the Giant Magnetoresistance Effect
D X. Yang, E J. Repetski, H D. Chopra, P J. Chen, William F. Egelhoff Jr.
Carbon (in the form of hydrocarbons) is a common contaminant in high and ultra-high vacuum systems, and easily gets incorporated in films during deposition. This work reports the highly deleterious role of small amounts of carbon on the structure and magnetic properties of giant magnetoresistance (GMR) spin valves. Controlled incorporation of 1 % to 3 % atomic fraction carbon in Co/Cu layers of NiO-Co-Cu-based spin valves has been found to completely eliminate the GMR effect. Tansmission electron microscopu (TEM) shows that carbon promotes highly discontinuous Co/Cu layers, resulting in a large number of pinholes; domain studies corroborate that the free layer under the influence of a large pinhole coupling is unable to switch independently of the pinned Co layer. These results also have implications for other multilayers and spintronics devices.
, Repetski, E.
, Chopra, H.
, Chen, P.
and Egelhoff Jr., W.
Highly Deleterious Role of Small Amounts of Carbon on the Giant Magnetoresistance Effect, Journal of Applied Physics
(Accessed September 30, 2023)