摘要：

Molecular spintronics is an emerging research eld exploiting the versatility of organic molecular electronics together with the spin degree of freedom as information carrier. Especially the use of functional organic molecules in this area opens perspective for highly integrated spintronic devices. Spin-crossover (SCO) molecules exhibit intriguing intrinsic functionality and therefore high potential for molecular spintronic applications. These complexes can exist in two distinct spin congurations with different optic, geo-metric and magnetic properties. Moreover, they can be specically switched between both states by external perturbations like temperature, pressure or light irradiation. However, the fascinating functionality is accompanied by a pronounced fragility of the molecular structure impeding applications in device-like environments, e.g., on metallic surfaces. The main goal of this thesis is therefore to identify the limitations and possibilities of novel, robust SCO molecules, including the interactions with different surfaces, as candidates for molecular opto-spintronic interfaces. To this end, the new SCO compound Fe(py(CF 3 ) 2 pyr) 2 (phen) (Fe-pypyr) was ex-amined regarding its fundamental SCO properties as bulk material and in thermally vacuum-evaporated thin lms ( ≥ 40 monolayer) on a Au(111) surface using near-edge x-ray absorption ne-structure (NEXAFS) spectroscopy. The spin-transition temperature, well above room temperature for the bulk complex, is drastically lowered in thin lms. Furthermore, while within the experimentally accessible temperature range ( 2 K < T < 410 K ) the bulk material shows indication of neither light-induced excited spin-state trapping nor soft X-ray-induced excited spin-state trapping, these effects are observed for molecules within thin lms up to temperatures of around 100 K . Thus, by arranging the molecules into thin lms, the nominal low-spin (LS) complex Fe-pypyr is effectively transformed into a spin-crossover complex. Based on these results, the further aim was to exploit the usually increased robust-ness of LS complexes together with the observed generation of SCO functionality after surface adsorption. Therefore, sub-monolayer coverages of Fe-pypyr were prepared on several substrates

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