The structure of GaAs(110) surfaces under the simultaneous presence of
antimony and bismuth monolayer adsorbates was investigated by combini
ng Raman scattering with low-energy electron diffraction and Auger spe
ctroscopy. Raman spectroscopy from surface vibrations was used to prob
e the bonding of the adsorbates with the GaAs surface. Both adsorbates
form a well-ordered surface monolayer when present alone on the surfa
ce. Independent of the order of deposition an Sb-covered surface alway
s forms when both adsorbates are present simultaneously. The formation
of an ordered monolayer containing both adsorbates does not take plac
e due to the higher stability of the Sb-terminated as compared to the
Bi-terminated surface. (C) 1998 Elsevier Science B.V.