Element-specific magnetism studies on patterned magnetic structures and magnetic films.

摘要

In continuous (Fe/Gd) and patterned (Fe/Gd, NiFe/Co) magnetic multilayer films, the effects of interfacial coupling, proximity, anisotropy (intrinsic and shape), and termination were investigated, and how they modify the magnetization reversal processes and magnetization depth profiles was studied. X-ray resonant scattering and absorption techniques combined with micromagnetic simulations were used to study films in an element specific and depth-resolved way.; In an aligned-phase Fe/Gd multilayer, the Gd layers near the Fe/Gd interfaces were studied using x-ray resonant magnetic scattering measurements. From the experimental results, the Gd layer-specific magnetization depth profiles were obtained. An enhanced magnetic ordering in the interfacial Gd layers was observed, and the observed results were consistent with theoretical calculation results and x-ray magnetic circular dichroism measurement results.; A termination layer effect and the role of magnetic anisotropy in the Fe layers were studied on different sets of Fe/Gd multilayers that showed twisted magnetic states. X-ray magnetic circular dichroism (XMCD) measurements were performed in a surface-to-bulk way. The experimental results were reproduced in micromagnetic simulations, and the observed features near the compensation point were explained by the combined effect of a termination layer and a magnetic anisotropy.; Magnetic domain configurations were studied in a hole array patterned Fe/Gd multilayer using XMCD measurements and micromagnetic simulations. The interplay between an intrinsic anisotropy and a shape anisotropy affected domain configurations, and coherent rotations of three types of domains were observed. Similarly, on a pseudo-spin-value type patterned film, local magnetization was measured using XMCD with micro-focused x-ray beams.; On patterned dot array films, it was demonstrated that the layer selective magnetization depth profiles could be obtained from patterned arrays using x-ray resonant magnetic scattering.