title: Angular first-order reversal curves: an advanced method to extract magnetization reversal mechanisms and quantify magnetostatic interactions.
abstract: The magnetic properties of ordered hexagonal arrays of Co nanowires (NWs) and nanotubes (NTs) with diameters of 50 nm and interwire/tube distances of 105 nm were studied using first-order reversal curves (FORCs). We report an advanced analysis of angle dependent first-order reversal curves (AFORCs), measured by changing the angle of the applied magnetic field from θ = 0° (parallel to the wire/tube axis) to 90° (perpendicular). This method allowed us to determine the magnetization reversal mode and to retrieve quantitative information on the magnetostatic interactions between NWs and between NTs. In particular, we found a sharp increase in the coercivity distribution of the NT arrays for θ > 70°, which is attributed to a transition between vortex and transverse reversal modes. Local magnetic interactions are found to prevail in the Co NT arrays, steadily increasing from θ = 0° to 90°. However, in the Co NW arrays the mean magnetic interactions decrease as θ increases, going from ones similar to local interactions to ones smaller than them.
authors.affiliation: IFIMUP and IN-Institute of Nanoscience and Nanotechnology and Departamento de Física e Astronomia, Universidade de Porto, Rua do Campo Alegre 687, 4169-007 Porto, Portugal.
authors.forename: M P
authors.initials: MP
authors.lastname: Proenca
authors.forename: J
authors.initials: J
authors.lastname: Ventura
authors.forename: C T
authors.initials: CT
authors.lastname: Sousa
authors.forename: M
authors.initials: M
authors.lastname: Vazquez
authors.forename: J P
authors.initials: JP
authors.lastname: Araujo
mesh_terms: D003035:Cobalt / Q000737:chemistry*; D060526:Magnetic Fields; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D043942:Nanotubes / Q000737:chemistry*; D053770:Nanowires / Q000737:chemistry*; D055672:Static Electricity
chemical_list: D003035:Cobalt