Resonant tunneling in magnetoresistive Ni/NiO/Co nanowire junctions

Abstract

Magnetotransport studies performed on electrodeposited Ni/NiO/Co nanojunctions show a broad distribution of magnetoresistance values spanning from +40% to −25%, with an average of about 2%, corresponding to observations on large-area junctions. The dispersion in the results can be understood in terms of tunneling via localized states in the barrier. Calculations based on Landauer–Büttiker theory explain this behavior in terms of disorder-driven statistical variations in magnetoresistance with a finite probability of the inversion of tunnel magnetoresistance sign due to resonant tunneling.