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Cylindrical soft magnetic Co films, nanostructured with a grain size of 1–2 nm and between and 90 nm in thickness, were produced by the pulsed laser deposition technique. These films showed a magnetostrictive property. The magnetoelastic inverse Wiedemann effect, or IWE, of longitudinal magnetization as a function of the circular applied magnetic field, Mz–H, was measured. The IWE made it possible to explain the magnetization processes according to an initial reversible rotation of the magnetization followed by magnetic wall nucleation and propagation. A magnetization rotation model allowed us to compare the reversible part and the first irreversible magnetization processes corresponding to the IWE. In this way, the values of the helical magnetic anisotropy, Kh, due to the helical stresses, σh, generated by an applied torque to the films, were determined. A linear increase of the nucleating magnetic wall field, HN, with the applied torque, or with σh, was observed. In addition, the IWE made it possible to establish the non-dependence of the saturation magnetostriction constant, λs, on the sample thickness and to determine the value of this negative isotropic .

The magnetic domain configurations of soft magnetic, nanostructured, pulsed laser-deposited Co films were investigated. Their dependence on both the thickness t (20 nm ≤ t ≤ 200 nm) and the anisotropy was studied. Charged zigzag walls, with a characteristic saw-tooth vertex angle θ, were observed. θ changed with t from θ ≈ 17° to ≈25°, presenting an intermediate sharp maximum that has not been described before. The reduced length of the zigzag walls also exhibited a peak at t ≈ 70 nm. The relationship between the total reduced length and the density energy of the magnetic wall allowed us to establish a change from a Néel-type to a Bloch-type core of the zigzag walls at this thickness, t ≈ 70 nm. We also accounted for the magnetic energy arising from the surface roughness of the thinner films after imaging the film surface morphologies. Moreover, this distinctive behaviour of the zigzag walls of these low-anisotropy films was compared to that of high-anisotropy films.