Giant tunnel magnetoresistance in codeposited fullerene-cobalt films in the low bias-voltage regime

Magnetotransport properties in the low bias-voltage regime were investigated for codeposited C 60 - Co films. A giant tunnel magnetoresistance (MR) ratio ( Δ R ∕ R max ) of 80%, which is the highest in ferromagnetic metal/organic molecule systems, was found at low temperatures. The observed bias-voltage dependence of the MR ratio is expressed by an unusual exponential form, suggesting that the MR ratio of nearly 100% can be realized in the low bias-voltage limit.