SCANNING-TUNNELING-MICROSCOPY STUDY OF ULTRATHIN FE FILMS GROWN ON GAAS(001) SURFACE

Scanning tunneling microscopy (STM) studies have been carried out to c larify the initial growth mechanisms of ultrathin Fe films on GaAs(001 ) substrates. For the submonolayer growth of Fe at room temperature (R T), the STM image showed many small clusters on the flat terraces of t he c(4 x 4) reconstructed GaAs(001) surface. The typical size of the c lusters seen in the STM image is about 15 Angstrom which is nearly equ al to the size of the basis structure of the c(4 x 4) reconstruction. It is also discussed that the formation of the clusters depends on the reconstruction of the GaAs(001) surface.