Morphological evolution of erbium disilicide nanowires on Si(001)

摘要

The morphological evolution of ErSi2 nanowires on Si(001) with Er coverage was investigated by scanning tunnelling microscopy, low-energy electron diffraction and x-ray diffraction. At low Er coverages, elongated ErSi2 nanowires in a hexagonal crystal structure are formed. The nanowires are exclusively oriented perpendicular to the dimer rows of the Si(001) substrate, thus suggesting a method to control the nanowire arrangement via the substrate configuration. At 3 ML of Er rectangular islands with flat tops are observed, which crystallize in the tetragonal lattice of ErSi2. Our experiments suggest that the structural transformation from hexagonal to tetragonal takes place when the nanostructures reach the height of the c-axis of the tetragonal unit cell. Copyright (C) 2004 John Wiley Sons, Ltd. [References: 24]