ABSTRACT
Monocrystalline layers of n-(Eu,Gd)Te ferromagnetic semiconductor were grown by molecular beam epitaxy technique on cleaved (111) BaF2 substrate. Structural as well as morphological characterization of epilayers carried out by standard x-ray diffraction and atomic force microscopy techniques proved their high crystal quality. Energy dispersive x-ray fluorescence analysis was used to determine the chemical composition of (Eu,Gd)Te samples showing Gd content up to 5 at. %. For magnetic characterization ac magnetic susceptibility and SQUID magnetization measurements were performed indicating ferromagnetic transition at Curie temperature T C=11-15 K. From magneto-optical Kerr effect measurements carried out at high fields the full saturation of magnetization in (Eu,Gd)Te layers was observed only for magnetic fields above B=10 T. The measurements of transport properties revealed characteristic increase of resistivity at the Curie temperature and large negative magnetoresistance.
