In dieser Arbeit wurden zwei verschiedene Wärmebadankopplungen an klassische Spin-Systeme realisiert. Zum einen wurde ein stochastischer Ansatz mittels Landau-Lifshitz-Dämpfung und Fluktuationen numerisch realisiert und zum anderen wurde ein vollkommen deterministischer Ansatz entworfen und optimiert. Mit Hilfe dieser Ankopplungsmethoden ist es möglich, sowohl statische magnetische Eigenschaften klassischer Spin-Systeme als auch deren dynamische magnetische Eigenschaften zu simulieren. Als Anwendung wurden Spin-Gitter-Relaxationszzeiten und Neutronenstreuquerschnitte für molekulare Magneten wie z.B. dem "ferric wheel" berechnet und mit aktuellen experimentellen Ergebnissen verglichen. Als zweite Anwendung wird die Magnetisierungsumkehr in einem sphärischen Teilchen diskutiert.

This thesis contains experimental studies on low dimensional systems by means of scanning tunneling microscopy (STM). These studies include investigations on dinickel molecular complexes and experiments on iron nanostructures used for the implementation of the spin-polarized scanning tunneling microscopy technique at the IFW-Dresden. Additionally, this work provides detailed information of the experimental technique (STM), from the theoretical background to the STM-construction, which was part of this doctoral work. Molecular anchoring and electronic properties of macrocyclic magnetic complexes on gold surfaces have been investigated by mainly scanning tunneling microscopy and complemented by X-rays photoelectron spectroscopy. Exchange–coupled macrocyclic complexes [Ni2L(Hmba)]+ were deposited via 4-mercaptobenzoate ligands on the surface of Au(111) single crystals. The results showed the success of gold surface-grafted magnetic macrocyclic complexes forming large monolayers. Based on the experimental data, a growth model containing two ionic granular structures was proposed. Spectroscopy measurements suggest a higher gap on the cationic structures than on the anionic ones. Furthermore, the film stability was probed by the STM tip with long-term measurements. This investigation contributes to a new promising direction in the anchoring of molecular magnets to metallic surfaces. Iron nanostructures of two atomic layers and iron-coated tungsten tips were used in order to implement the spin-polarized scanning tunneling microscopy technique at the IFW-Dresden. First of all, a systematic study of the iron growth, from sub-monolayers to multilayers on a W(110) crystal is presented. Subsequent to the well-understanding of the iron growth, the experiments were focused on revealing, for the first time at the IFW-Dresden, the magnetic inner structure of iron nanostructures. The results evidently showed the presence of magnetic domains of irregular shapes. Furthermore, SP-STM probed the bias voltage dependence of the magnetic contrast on the iron nanostructures. This technique opens up a new powerful research line at the IFW-Dresden which is promising for the study of quantum materials as molecular magnets and strongly correlated systems.

This thesis contains experimental studies on low dimensional systems by means of scanning tunneling microscopy (STM). These studies include investigations on dinickel molecular complexes and experiments on iron nanostructures used for the implementation of the spin-polarized scanning tunneling microscopy technique at the IFW-Dresden. Additionally, this work provides detailed information of the experimental technique (STM), from the theoretical background to the STM-construction, which was part of this doctoral work. Molecular anchoring and electronic properties of macrocyclic magnetic complexes on gold surfaces have been investigated by mainly scanning tunneling microscopy and complemented by X-rays photoelectron spectroscopy. Exchange–coupled macrocyclic complexes [Ni2L(Hmba)]+ were deposited via 4-mercaptobenzoate ligands on the surface of Au(111) single crystals. The results showed the success of gold surface-grafted magnetic macrocyclic complexes forming large monolayers. Based on the experimental data, a growth model containing two ionic granular structures was proposed. Spectroscopy measurements suggest a higher gap on the cationic structures than on the anionic ones. Furthermore, the film stability was probed by the STM tip with long-term measurements. This investigation contributes to a new promising direction in the anchoring of molecular magnets to metallic surfaces. Iron nanostructures of two atomic layers and iron-coated tungsten tips were used in order to implement the spin-polarized scanning tunneling microscopy technique at the IFW-Dresden. First of all, a systematic study of the iron growth, from sub-monolayers to multilayers on a W(110) crystal is presented. Subsequent to the well-understanding of the iron growth, the experiments were focused on revealing, for the first time at the IFW-Dresden, the magnetic inner structure of iron nanostructures. The results evidently showed the presence of magnetic domains of irregular shapes. Furthermore, SP-STM probed the bias voltage dependence of the magnetic contrast on the iron nanostructures. This technique opens up a new powerful research line at the IFW-Dresden which is promising for the study of quantum materials as molecular magnets and strongly correlated systems.