Surface Structures Formed during the Interaction of Sulphur Compounds with the (111) Face of Nickel

The interaction of hydrogen sulphide, n-propyl mercaptan, and dimethyl disulphide with the (111) and (100) faces of nickel has been studied by LEED at temperatures up to 700 K. During interaction and subsequent annealing, in vacuo below 10−9 Torr at temperatures up to 1200 K, series of diffraction patterns were observed. Four of the patterns on (111) have been attributed to coincidence nets arising from structures which involve rearrangement and reorientation to (100) type layers. The patterns are described and the interpretations discussed.