Clean (001)-(4 x 2) and H2S-treated (1 x 2) surfaces were studied by means of scanning tunneling microscopy. A (4 x 2)/c(8 x 2) image was observed in the case of the cation-stabilized (001) surface. The results suggested that the unit cell of the (4 x 2) structure consisted of two Ga dimers with 2 missing Ga dimers. In the case of the (1 x 2)S surface a previous model, which assumed that S atoms were adsorbed at the Ga dimer and that a missing row of S formed along the [1¯10] direction, was supported by the scanning tunneling microscopic results.

N.Sanada, M.Shimomura, Y.Fukuda, T.Sato: Applied Physics Letters, 1995, 67[10], 1432-4