Kuncser, V., Keune, W.
Step-shape angular spin distribution in layered systems by 57Fe Mössbauer spectroscopy: A general treatment
Journal of Magnetism and Magnetic Materials 323, (16),pp 2196-2201 (2011)
In the so-called 'step-shape' angular spin distribution model for layered systems, the non-collinear directions of the atomic magnetic moments are confined to the film plane and form a homogeneous fan spanning inside an (in-plane) angular interval ∆ϕ centered at an angle ϕ0. A general approach for deriving the two parameters ϕ0 and ∆ϕ via 57Fe Mössbauer spectroscopy measurements is discussed. The analysis extends our previously reported treatment, which assumed that the angular aperture ∆ϕ develops symmetrically versus a fixed direction ϕ0 (e.g., the in-plane easy axis of magnetization) oriented either along or perpendicular to the in-plane projection of the Mössbauer γ-ray direction. The proposed approach is also applicable for those cases when not only the spin aperture ∆ϕ is changing but also the aperture center ϕ0 is rotating under the influence of different external parameters, such as applied field, temperature, stress, etc. The method is suitable for applications to nanoscale layered heterostructures with in-plane uniaxial or unidirectional magnetic anisotropy. The method is applied to experimental data obtained on a 2-nm thick defected Fe layer with in-plane magnetic texture.