Sammendrag
We present the first experimental results from homoepitaxial growth o f Co on Co(11-20) studied by scanning tunneling microscopy (STM). The unreconstructed Co(11-20) surface consists of zigzag rows of atoms r unning along the [0001] direction of the Co crystal. CO adsorption ha s been found to induce highly anisotropy Co diffusion on this surface [1]. Upon deposition of small amounts of Co on Co(11-20) at room t emperature Co islands elongated along the [0001] direction are observ ed. The Co islands are nucleated both inside terraces and at step edg es. Preferentially, nucleation occurs at step egdes intersecting the [0001] direction. The shape of the islands indicate that the homoepit axial growth process is anisotropic. Further deposition of Co caus es the islands to grow in size and to coalesce with neighbouring isla nds. When 60-70% of the Co(11-20) surface is covered with first layer islands, second layer islands are observed to nucleate on top of the first layer islands. In the submonolayer regime, the island position s and size distribution, as a function of substrate temperature (~300 -500K), will be discussed. [1.] H. J. Venvik, A. Borg and C. Ber g, Surf. Sci. Vol 397, (1998), 322-332.
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