Growth, Structure and Magnetism of gamma-Mn on Pt(111) and CoPt_3(111) on WSe_2(111)

This diploma thesis shows the influence of substrates on the physical properties of epitactically grown films on the basis of two examples:the high temperature modification gamma-Mn has been stabilized on Pt(111)at room temperature by means of molecular beam epitaxy (MBE). The structural examinations have been performed with RHEED and XRD. The fcc-unit cell is tetragonally distorted, due to the lattice mismatch. Magnetization measurements could not prove a theoretically predicted, ferromagnetic ordering for distorted Mn.The second example is the stabilization of magnetic CoPt_3 nanostructures on WSe_2. Below the coverage of one monolayer the adatoms form statistically distributed, hexagonal, facetted and single-cristalline islands. At deposition temperatures of 150°C or higher the islands are in addition chemically ordered. The magnetic properties of CoPt_3 films are of great interest for technical applications. The films consist of 10nm-sized clusters with perpendicular magnetic anisotropy at deposition temperatures below 100°C. Both, the cluster size and the perpendicular magnetic anisotropy, promise a drastical enhancement of the data storage density. Moreover, the production process of such storage material is extremely simple as only one production step is necessary with the deposition temperature being at room temperature