Absence of weak electron localization in (Co/Pt)n-multilayer-nanowires with perpendicular anisotropy

We report on low temperature resistance and magnetoresistance (MR) measurements for various (Co/Pt)(n)-multilayer-nanowires with perpendicular magnetic anisotropy and different widths, designed as model systems for the experimental observation of weak electron localization effects in ferromagnetic systems as proposed by Dugaev et al. [Phys. Rev. B 64, 144423 (2001)]. The low temperature MR is found to originate from both the anisotropic MR and domain wall scattering. The temperature dependence of the resistance shows a logarithmic resistance increase with decreasing temperature, as it is typical for quantum corrections in two dimensional systems. Upon application of a perpendicular magnetic field, however, the slope of the logarithmic resistance increase does not change in magnitude, which proofs that weak localization effects are not present, at least within the accuracy of our measurements. Instead, the observed quantum corrections of the resistance are well explained by enhanced electron-electron interaction effects in two dimensions. The results are discussed with regard to recent experimental as well as theoretical works. (c) 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.