Electron-electron interaction in quasi-one-dimensional cobalt nanowires capped with platinum: Low-temperature magnetoresistance measurements

We have measured the low-temperature magnetoresistance of single cobalt nanowires with various widths ranging between 400.3em0exnm and 20.3em0exμm prepared by electron beam lithography. The wires are protected in situ with 20.3em0exnm platinum to prevent oxidation. The temperature dependence of the resistance shows a logarithmic increase to low temperatures which is attributed to enhanced electron-electron interactions in two dimensions. The strength of interaction effects increases with decreasing width of the wires and a transition to a quasi-one-dimensional behavior is observed. We do not find any contribution due to weak electron localization in agreement with previous results on similar carbon covered nanowires.