Surface reconstructions and faceting of the Ga/Ge(113) system

Surfaces of the Ga/Ge(113) system have been studied by means of low-energy electron diffraction (LEED) and scanning tunneling microscopy (STM). It has been found that the only two reconstructions of the system, i.e., ((8)(-1)(5)(1)) and ''1 x 2'', consist of the same (I x 2)-like building blocks and, hence have only slightly different coverages. Coexisting with the reconstructions are small (112) and (115) facets, which develop through bunching of steps. On the basis of LEED patterns and STM images and under the guidance of the common characteristics of surface structures of III/IV systems, structural models have been proposed for these reconstructions and the (112) facets for further investigation. It has been noticed that only small percentages of a monolayer of Ga can make the Ge(113) surface entirely 3 x1; otherwise it contains a great many small 3 x2 patches scattered inside large 3 x1 domains. (C) 1997 Elsevier Science B.V.