New Erbium Silicide Superstructures: A Study by High Resolution Electron Microscopy

Abstract

Erbium silicide thin films are grown on Si(100) substrates under high vacuum by single deposition of Er or co‐deposition of Er and Si, followed by annealing. Electron microscopy revealed for both preparations the existence of at least three new types of structural phases of erbium silicide. One has a tetragonal ThSi2 type structure; the other two are orthorhombic superstructures of the first one resulting from ordering of vacancies on the Si sublattice, which leads to a composition of ErSi2−x (0 < x < 0.5).

Medium-energy ion-scattering study of strained holmium silicide nanoislands grown on silicon (100)

“…Characteristic 'wires' measuring up to a micrometre in length, and typically only a few nanometres wide were observed by scanning tunneling microscopy (STM). This discovery and the potential technological applications of such conducting nanowires has motivated considerable interest over the last ten years [2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28]. Chen et al have demonstrated that the growth of nanowires with extremely high aspect ratios is the result of the anisotropic lattice mismatch that results from the growth of the hexagonal, defect-AlB 2 RE silicide on the Si(100) surface (see Fig.…”

“…Depositing more RE metal causes islands to form with the surface displaying a c(2 × 2) periodicity. The structure of these RE silicide islands has been proposed to be either hexagonal, tetragonal (ThSi 2 ) or orthorhombic (GdSi 2 ) [1,6,10,12,13,16,17,22,27,28]. All three of these phases are known to exist in the bulk and their lattice constants have been measured and it is known that the bulk orthorhombic phase is only a small distortion of the tetragonal phase [29].…”