X-ray resonant magnetic scattering study of [Co₂MnGe/Au]_nand [Co₂MnGe/V]_nmultilayers

Abstract

Abstract. We study the structure and magnetism of the ferromagnetic half metallic Heusler compound Co 2 MnGe in high-quality [Co 2 MnGe/Au] n -and [Co 2 MnGe/V] n -multilayers by hard x-ray scattering and soft x-ray resonant magnetic scattering (XRMS). The diffuse hard x-ray scattering reveals that in [Co 2 MnGe/Au] n at the interfaces correlated roughness dominates and interdiffusion is negligible, whereas in [Co 2 MnGe/V] n the roughness is uncorrelated and dominated by interdiffusion. An analysis of energy-dependent scans in the soft x-ray regime at the superlattice Bragg peaks allows a determination of the element specific magnetic moment density profile within the Co 2 MnGe layers. We find that the magnetic moment density profile determined for Co and Mn is definitely different, moreover, it is narrower than the chemical density profile and asymmetric with respect to the growth direction. For [Co 2 MnGe/Au] n at room temperature a non-ferromagnetic interface layer with a thickness of about 0.6 nm at the bottom and 0.45 nm at the top of the Co 2 MnGe layers exist, for [Co 2 MnGe/V] n at the bottom and the top the corresponding thicknesses are 0.5 nm and 0.35 nm, respectively.

Direct in-depth determination of a complex magnetic configuration in an exchange-coupled bilayer with perpendicular and in-plane anisotropy

“…Typically, this technique is performed by analyzing the energy dependence of the reflectivity at different angular or scattering vector values, [3][4][5][6][7][8] whereas recently strong interest has emerged in the analysis of the angular dependence of the reflectivity close to an absorption edge. [9][10][11][12][13] This turns out to be particularly relevant in the soft x-ray range where the reflectivity measured at large scattering angles is sensitive to out-of-plane magnetization.…”

Improvement of structural, electronic, and magnetic properties of Co2MnSi thin films by He+ irradiation

“…However, high temperature annealing often leads to interdiffusion and local changes of the stoichiometry in Heusler compounds [13]. For FePt thin layers, however, it has been demonstrated that the degree of chemical order can alternatively be controlled by post-growth irradiation with He + ions [14,15].…”

10.1007/s11451-008-2022-z

“…Different models can be used for the form factor depending on the film structure. When the mixing of atoms at the interfaces is absent, the quantity ∆ k for the bilayer can be represented in the framework of the step model: (6) where θ(z) is the Heaviside theta function and C a and C b are constants. In the framework of this model, the permittivities in each metal layer are constant and change abruptly upon changing over to the metal of another type.…”

“…In particular, it has become possible to analyze not only static properties but also dynamic properties of nanostructures on the atomic level by measuring the time correlation functions of the x-ray intensity [2][3][4]. Moreover, the use of polarized x-ray radiation has made it possible to investigate magnetic properties [5,6].…”