Morphological evolution of erbium disilicide nanowires on Si(001)

Abstract

The morphological evolution of ErSi 2 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 ErSi 2 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 ErSi 2 . 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.

Structural and Chemical Properties of Gold Rare Earth Disilicide Core−Shell Nanowires

“…Scanning tunneling microscopy (STM) images of DySi 2 nanowires on the p-type Si(001) surface before and after Au deposition are shown in Figure a and b, respectively. In Figure a, we show that the DySi 2 nanowire surface before Au deposition exhibits a c(2 × 2) reconstruction, as was also observed by others for DySi 2 and ErSi 2 nanostructures. Meanwhile, the neighboring regions comprise both (2 × 1) reconstructed Si(001) surface manifested by Si dimer rows and complex Dy−Si metal reconstructed regions.…”

Thermodynamic driving forces governing assembly of disilicide nanowires

“…5(b) and (c), respectively. A variety of other nanowire surface reconstructions have been observed, such as p(1 × 1) and c(2 × 2), for DySi 2 − x [10,48] and ErSi 2 − x [50] nanowires. These may be due to Si vacancies, which are thought to reduce the strain caused by lattice mismatch [46].…”

STM and DFT study of the Gd wetting layer reconstructions on the Si(001)-2×1 surface

“…A major impetus for such studies is the search for new, cost effective methods to fabricate nanometer scale electronic devices. One system that has been investigated for this purpose is rare-earth (RE) silicides on the Si(1 1 1) [1][2][3] and Si(0 0 1) [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] surfaces. As first shown by Preinesberger et al [4], nanowires form in the initial growth stages of silicide overlayers for many RE metals, including: Dy [3][4][5][6][7][8][9][10], Er [5][6][7][11][12][13][14], Ho [6,9,15], Gd [1,2,7,16], Sc [7], Yb [17], Sm [5]...…”