TY  - GEN
UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/13794/
AV  - public
A1  - Lutz, Matthias Uljas
TI  - A Magnetic Force Microscopy Investigation of alpha-Fe, Fe3C and Permalloy Nanowires under Applied Magnetic Fields
N2  - This thesis provides experimental insight into the role of anisotropies in magnetic wires at the nanoscale. While fundamental properties of magnetic nanowires are well described theoretically, real systems are subject to imperfections which in particular affect the mechanism and dynamics of magnetization reversal. Therefore, not only fundamental material parameters but also detailed investigations of the field dependent magnetic properties are essential before the vast potential of magnetic nanowires can be exploited. In the thesis at hand, a magnetic force microscope (MFM) with internal magnetic fields was employed to study the remanent behavior of the nanowires and the effects of applied fields. A physical characterization allows one to connect the morphology of the wire to its magnetic response. The magnetic characteristics of two types of nanowires are studied. Firstly, alpha-Fe and Fe_3C nanowires naturally formed within multiwalled carbon nanotubes. Secondly, tailored nanowires arranged in patterns causing well defined interactions. For the carbon coated nanowires, the results highlight the importance of anisotropies in deciding the behavior of magnetic nanowires. For the artificial nanostructures, frustration imposed on the single domain magnets yields novel effects highlighting that the wires can be used as a model system for quantum processes. In both cases the shape, either imposed by the rigid cage of a carbon nanotube or tailored to ones specifications, is crucial in the context of the magnetic properties. Also the MFM tip itself plays a deciding role as it can cause switching in the magnet it is measuring. The results give new insight into the physics of magnetic nanowires and lay the groundwork for potential applications.
Y1  - 2012///
ID  - heidok13794
KW  - MFM
ER  -