Magnetism and Spintronics: Research Activities at the IFF Jülich

Invited by Nick Barrett The understanding of spin-dependent transport processes and their control in advanced microelectronic devices are the central issues in “spintronics”, currently being the main driving force in magnetism research. The functionality of devices will ultimately be governed by the electronic and magnetic properties at the interfaces and by nanoscale aspects. As a consequence, spintronics research covers all facets of magnetism on short length and time scales, including a strong materials science component as well. Our research program at the IFF-9 is devoted to the fundamental aspects of spintronics. In this course it addresses the interplay between electronic structure and magnetic properties of selected material systems, the formation of spin structures at surfaces and interfaces, and the magnetization and spin dynamics. The studies employ a variety of spectroscopy, microscopy, and scattering approaches involving VUV and soft X-ray synchrotron light. In my presentation I will illustrate the research program by some examples for spectroscopy and microscopy studies of spintronics model systems, such as MgO/Fe(001) as a paradigm of a tunneling magnetoresistive interface. A prototype system for the coupling between ferro- and antiferromagnets is Fe₃O₄/NiO, which we investigated extensively by means of photoemission microscopy (figure: domain structure at the (111) surface and reconstructed magnetization distribution). In the final section I will turn to time-resolved and element-selective microscopy investigations of magnetization dynamics down to the ps-regime, exploiting the intrinsic time-structure of synchrotron radiation.

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Inst. f. Festkörperforschung IFF-9, Forschungszentrum Jülich, Germany