Absence of weak electron localization in carbon-covered Co-nanowires

We have investigated the low temperature resistance and magnetoresistance behavior of ferromagnetic cobalt wires in perpendicular external magnetic fields of up to B=5 T. Magnetic force microscopy investigations show that the cobalt wires are single-domain at remanence, if the wire width is smaller than about 800 nm. At low temperatures a logarithmic resistance increase is observed which is consistently explained as originating from enhanced electron-electron interaction (EEI) in two dimensions, while the magnetoresistance is dominated by the anisotropic magnetoresistance. Additional resistance corrections due to weak electron localization (WEL) are not observed within the accuracy of our measurements, which is discussed in the framework of recent experimental and theoretical works.