FABRICATION AND MAGNETOOPTICAL PROPERTIES OF EPITAXIAL FERROMAGNETIC MN1-XSB THIN-FILMS GROWN ON GAAS AND SAPPHIRE

We succeeded in growing epitaxial ferromagnetic Mn1-xSb thin films by molecular beam epitaxy (MBE). The crystal structures were of NiAs-type and their orientations changed depending on the substrate, (10.1) for (001) GaAs and (00.1) for (00.1) sapphire, The sharp X-ray diffraction patterns showed that these epitaxially grown films were of the highest crystal quality reported so far. Under the present growth conditions, the compositions I of the films were automatically settled to be about 0.2 (Mn0.8Sb) which was determined by electron probe microanalysis and Auger analysis. The Curie temperature, T-C, was about 620 K, which was evaluated by the temperature dependence of the magnetization of the film grown on the GaAs substrate, The polar magneto-optical Kerr rotation spectrum of the film on the GaAs substrate was almost the same as that reported previously in the bulk samples. However, the spectrum of the (10.1) film on the GaAs substrate revealed a clearly different structure compared with that of the (00.1) film on the sapphire substrate.