The surface structures formed by deposition of 0.25 ML and 0.50 ML Bi on Cu{100} at room temperature have been determined quantitatively using the symmetrised automated tensor low energy electron diffraction (SATLEED). At y Bi ¼ 0.25 ML, Bi forms a semi-ordered p(2 Â 2) surface alloy with the Bi atoms located at a height of 0.56 AE 0.06 A ˚with respect to centre of gravity of the buckled outermost Cu layer (buckling amplitude ¼ 0.11 A ˚). The interlayer spacings in the first three substrate layers are found to be:The first and the third Cu layers are found to be buckled by 0.11 AE 0.06 A ˚and 0.05 AE 0.06 A ˚, respectively. At higher Bi coverage, de-alloying occurs culminating in formation of a well ordered c(2 Â 2) overlayer at y Bi ¼ 0.50 ML. Bi atoms occupy the four-fold hollow sites with a vertical Bi-Cu interlayer separation of d Bi-Cu ¼ 2.17 AE 0.06 A ˚above a slightly perturbed substrate. The interlayer spacing in the first four substrate layers are found to be:A small buckling of 0.02 AE 0.02 A ˚is detected in the second Cu layer in which Cu atoms below Bi atoms are rippled outwards. The structures obtained by LEED are compared to those evaluated recently for the same system by surface X-ray diffraction.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.