Magnetic force microscopy and micromagnetic simulations on domains of structured ferromagnets [Elektronische Ressource] / vorgelegt von Miriam Barthelmeß geb. Halverscheid

Magnetic-force microscopyandmicromagnetic simulationson domains ofstructured ferromagnetsDissertationzur Erlangung des Doktorgradesdes Fachbereichs Physikder Universitat? Hamburgvorgelegt vonMiriam Barthelmeßgeb. Halverscheidaus BochumHamburg2003Gutachter der Dissertation: Prof. Dr. U. MerktProf. Dr. W. HansenGutachter der Disputation: Prof. Dr. U. MerktProf. Dr. D. HeitmannDatum der Disputation: 13. Mai 2004Vorsitzender des Prufungsaussc? husses: Dr. S. KettemannVorsitzender des Promotionsausschusses: Prof. Dr. R. WiesendangerDekan des Fachbereichs Physik : Prof. Dr. G. HuberAbstractIn this thesis, the magnetization of microstructured ferromagnets is studied withhelp of computer simulations in comparison to experiments. As experimentaltechniques magnetic-force microscopy and Hall „-magnetometry are used. Thelatter measures the stray field generated by ferromagnetic elements in externalmagnetic fields. Comparison to simulated hysteresis curves of the magnetizationgives the possibility to analyze the coercive and saturating fields of the particles.However, no statements can be made about the signal strength. For this reason,a computer code has been developed, which uses the output data of the micro-magnetic simulations to calculate the stray field in arbitrary distances above thesample. The magnetization data is therefore interpreted as magnetic dipoles inthe lattice cells, which have been defined for the simulation.