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MA: Fachverband Magnetismus
MA 4: Bio- und molekularer Magnetismus
MA 4.3: Talk
Monday, March 7, 2016, 10:00–10:15, H33
The Optical and Thermal Spin State Manipulation of Fe(bpz)2bipy and its Derivative Compounds on Graphite Surface — •Lalminthang Kipgen1, Holger Naggert2, Matthias Bernien1, Fabian Nickel1, Lucas M. Arruda1, Andrew J. Britton1, Felix Tuczek2, and Wolfgang Kuch1 — 1Institut für Experimentalphysik, Freie Universität Berlin, Germany — 2Institut für Anorganische Chemie, Christian-Albrechts Universität zu Kiel, Germany
The control of the spin state of molecules from the high-spin (HS) to the low-spin state (LS) or vice versa by thermal and optical means is envisioned to provide the ultimate building blocks for future spintronic devices. To this end, the understanding of the nature of the interaction of molecules and surfaces is crucial. Various molecule-substrate systems have been studied, and for sub-monolayer coverages, the transition is often quenched or co-existence of HS and LS at all temperature has been reported. Here, we report the thermal and optical manipulation of the spin states of submonolayers of Fe(bpz)2bipy, Fe(bpz)2bipy-me2 and Fe(bpz)2bipy-tert(butyl) on highly oriented pyrolytic graphite surface, using x-ray absorption spectroscopy. All the molecules are found to be HS stabilized at 300 K, but they exhibit contrasting spin state behavior at low temperatures. Only Fe(bpz)2bipy undergoes complete thermal spin state switching at low temperatures. It exhibits complete spin state conversion from LS to HS at 5 K by illumination with green light, and can be converted back to LS by increasing the temperature to 60 K. This work is supported by DPG through sfb 658 and sfb 677.