Growth, characterization and electrical properties of gadolinium silicide thin layers

The growth of gadolinium silicide (GdSi2-x) layers on Si(100) has been studied by scanning electron microscopy, X-ray diffractometry, Rutherford backscattering spectrometry and nuclear reaction analysis techniaues. The GdSi2-x layers are polycrystalline with an orthorhombic structure and a large number of Si vacancies. Non-uniform spatial diffusion of Si atoms into the metal film leads to a columnar growth of the silicide layer with rough surface and interface. Better layers are obtained with the deposition of multilayer structures of Gd and amorphous Si. Resistivity measurements in the temperature range 4.6–300 K show that the GdSi2-x layers are metallic with a magnetic ordering transition at 19 K.