The surface structure of CoGa(100) was studied by means of thermal-energy helium-atom scattering, low-energy electron diffraction, and Auger electron spectroscopy. A c(4 x 2) surface reconstruction was revealed by low-energy electron diffraction and thermal-energy helium-atom scattering measurements. Sometimes this reconstruction was mixed with a (√5 x √5) reconstruction, which was found to be due to a very minor contamination with oxygen. Only double-layer steps were found on the surface. Above 500K, the reconstructed layer starts to disorder, but short-range ordering in this layer was still observed until 700K. Near 900K, segregation of Co was observed with Auger electron spectroscopy. The increase of the cobalt concentration was consistent with filling up the 0.25ML, necessary for the c(4 x 2) reconstruction, to a completed monolayer at 900K. This interpretation implies that the surface was always terminated by Co.

Reconstruction of the CoGa(100) Surface Studied by Thermal-Energy Helium-Atom Scattering, LEED and Auger Electron Spectroscopy. F.M.Pan, C.Pflitsch, R.David, L.K.Verheij, R.Franchy: Physical Review B, 2001, 63[12], 125414 (7pp)