LEED ANALYSIS OF THE ADSORPTION STRUCTURE OF C(2X2)S/NI(100) INCLUDING SUBSTRATE MODIFICATIONS

We present LEED structure determinations of c(2 × 2)S Ni(100) both by a conventional R-factor analysis and a recently developed direct method. The adsorption height of sulfur in the hollow site results to be 1.30 ± 0.02 Å. The adsorbate is found to induce almost no substrate reconstruction and only a slight 2 ± 1 % expansion of the first substrate layer distance. The results are compared to earlier structure determinations, to theoretical predictions and to the structure recently obtained for the similar system c(2 × 2)O Ni(100). © 1990.