title: Spin configuration in isolated FeCoCu nanowires modulated in diameter.
abstract: Cylindrical Fe28Co67Cu5 nanowires modulated in diameter between 22 and 35 nm are synthesized by electroplating into the nanopores of alumina membranes. High-sensitivity MFM imaging (with a detection noise of 1 μN m(-1)) reveals the presence of single-domain structures in remanence with strong contrast at the ends of the nanowires, as well as at the transition regions where the diameter is modulated. Micromagnetic simulations suggest that curling of the magnetization takes place at these transition sites, extending over 10-20 nm and giving rise to stray fields measurable with our MFM. An additional weaker contrast is imaged, which is interpreted to arise from inhomogeneities in the nanowire diameter.
authors.affiliation: Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), 28049, Madrid, Spain. McGill University, H3A 2T8, Montreal, Canada.
authors.forename: Óscar
authors.initials: Ó
authors.lastname: Iglesias-Freire
authors.forename: Cristina
authors.initials: C
authors.lastname: Bran
authors.forename: Eider
authors.initials: E
authors.lastname: Berganza
authors.forename: Ignacio
authors.initials: I
authors.lastname: Mínguez-Bacho
authors.forename: César
authors.initials: C
authors.lastname: Magén
authors.forename: Manuel
authors.initials: M
authors.lastname: Vázquez
authors.forename: Agustina
authors.initials: A
authors.lastname: Asenjo