In-situ neutron reflectometry and studies of EuO films

In the framework of this thesis a sputtering system, which allows the in-situ analysis of sputtered films by means of neutron reflectrometry, was taken into operation. For this a software in LabView was generated, by which the whole system can be remotely controlled. As first actual theme of research by means of the in-situ neutron reflectometry the magnetic order of thin iron layers was studied. In the second part of this thesis the ferromagnetic semiconductor EuO was studied. By means of the MBE-grown EuO films could be shown that for a commensurate growth on substrates with positive lattice mismatchings a reduction of the Curie temperature can be observed. So 1.5 nm thick EuO films grown on the substrates YSZ(001), LuAlO₃(110), and YAlO₃ show a continuously decreasing T_C with increasing positive lattice mismatch. Furthermore it was shown that biaxially stressed and unstressed EuO films at identical thicknesses exhibit also different Curie temperatures. Furthermore the doping behaviour of EuO films with iron, lanthanum, and lutetium was studied.