Atomic resolution scanning tunnelling microscopic images were obtained of InSb(100) which had been prepared by using an in situ treatment which involved several cycles of low-energy Ar ion bombardment and annealing. The images revealed that the structural quality of the surface improved markedly during repeated bombardment and annealing cycles. After annealing at up to 625K, atomically flat terraces were obtained with areas of more than 100nm x 100nm. Room-temperature low-energy electron diffraction studies revealed a sharp stable c(8 x 2) pattern. Atomic resolution images revealed (4 x 1) unit cells in which occupied lone-pair orbitals of Sb atoms in the second layer were present. The data were consistent with a structural model, for this surface, in which ¾ of a monolayer of In dimers lay on top of a complete monolayer-Sb terminated surface.

M.O.Schweitzer, F.M.Leibsle, T.S.Jones, C.F.McConville, N.V.Richardson: Surface Science, 1993, 280, 63-70