Strukturelle Gesichtspunkte der magnetischen Zwischenschichtkopplung im Fe/Cr/Fe-System

A procedure was developed to prepare (001)-iron multilayers of the highest epitaxial quality on GaAs substrates which entails an iron seed layer and a silver buffer. The Fe/Cr/Fe double layers are deposited onto this buffer. The epitaxial and crystalline quality of the layers was investigated with SPA-LEED, RHEED, Auger, RBS and X-ray diffraction. The silver surface was found to be better than comparable surfaces of silver single crystal substrates and constitutes an ideal seed for the growth of iron layers. The investigation of the magnetic properties of Fe single and double layers prepared on these silver buffers with the Kerr-effect, FMR, Faraday and vibration magnetometry demonstrated the high quality of the samples, which almost achieve whisker standards. In the course of this dissertation the wedge-sample geometry was introduced to the investigation of the thickness dependent interlayer coupling. This magnetic interlayer coupling of the Fe/Cr-system was measured with the Kerr-effect, light scattering, Kerr microscopy and neutron diffraction. The long period oscillation in single crystal samples, ferromagnetic regions between the antiferromagnetic ones and a new form of coupling, the socalled 90 coupling, were discovered. Parallel to two other groups we were the first to measure a 2 monolayer short period oscillation by means of an electron bombardment of the Cr-interlayer. By raising the substrate temperature during evaporation the short period oscillation of the coupling strength could be observed to very large Cr-thicknesses. These samples, using easily accessible GaAs substrates, are the only ones that show the short and long period oscillations in the Fe/Cr-system apart from whisker samples. (orig.)SIGLEAvailable from TIB Hannover: RA 831(2743) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman