Effect of surface defects and adsorbates on the optical anisotropy of Cu(110)

Ion bombardment of Ni(110) studied with inverse photoemission spectroscopy and low-energy electron diffraction

“…In that study, the authors find close agreement between their integrated RAS signal intensity at various sputtering doses and the simulated fraction of surface cells not contained in circular patches of about 19 unit cells surrounding defects. This is supported by other studies [29] [30] on the same system with adsorbates and a variety of defects where cells not within ~20 unit cell patches were proposed to support the measurement signal.…”

Estimating the range of influence of point defects on Cu (110) surface states

“…10 It has been suggested by Sun et al, in studies focusing on the adsorption of CO (Ref. 9) and O (Ref.…”

“…Surface-state-related RAS features such as this are well known to be highly sensitive to molecular adsorption, [8][9][10] temperature, 10-12 surface alloying, 13 and the creation of surface defects via heating 14 and ion bombardment at low temperatures. 10 It has been suggested by Sun et al, in studies focusing on the adsorption of CO (Ref.…”

“…In this investigation, we build upon the work of Lane et al 10 by applying an analytical approach, based on the Poelsema and Comsa formalism, that incorporates knowledge, acquired via STM measurements, of the coverage and spatial distribution of surface defects created via ion bombardment. The STM results of this study have enabled us to improve upon the approach of our previous work 10 by eliminating its reliance on predictions of two crucial factors: the sputter yield (i.e., the number of defects created per ionic impact) and the extent to which these defects interact to produce clusters.…”

“…9, we have recently employed the Poelsema and Comsa formalism to model the effects of various types of surface defects on the Cu (110) 2.1 eV RAS feature, including adsorbates such as CH 3 SH, Si, Na, and CO, and irradiation and thermally generated adatoms. 10 The simulation, which incorporates (i) changes in the associated surfaces states with temperature, and (ii) the assumption that the defects exist in a randomly distributed "lattice-gas," indicates that all the defects investigated 10 quench the 2.1 eV RAS peak with a similar effective cross section with area equivalent to a circular patch with radius R D in the range 0.5 R D 1.0 nm.…”