X-ray diffraction of some technologically important surfaces

Surface X-ray diffraction (SXRD) has been used to study the effect of pressure and temperature on the Ni(110)-(2x1)-2CO reconstruction and the effect of temperature on the InSb(001)-c(8x2) reconstruction. The Ni(110)-(2x1)-2CO reconstruction was observed at a carbon monoxide pressure of 2.3 bar and has a structure unchanged from that at 1 x 10 -5 mbar. This structure was found to consist of CO molecules near short bridge sites in agreement with other recent studies in high vacuum conditions. Heating at 1 x 10-5 mbar causes a lifting of the (2x1) reconstruction due to desorption of the CO. In contrast, heating in 2.3 bar of CO leads to a massive rearrangement of the surface and the formation of {lcub}111{rcub} microfacets. The base of the microfacets is ≈100 A across and their surfaces are disrupted from the bulk terminated (111) surface. This is consistent with an enlargement of the lattice due to the dissolution of carbon in the facets.;SXRD and LEED experiments on the c(8x2) reconstruction of InSb (001) show no structural changes on cooling from room temperature to 74K. Key features of the reconstruction are determined which are at variance with the recent model of Jones et al..