Formation of an ordered surface compound consisting of Ag, Si, and H on Si 001/

With scanning tunneling microscopy and low energy electron diffraction, we have studied formation of a surface compound with Ag, Si and H on Si 001.. In contrast to the case of Si 111.– ʹ3 =ʹ3.Ag, on which adsorption of H atoms brings no homogeneous phases, moderate H adsorption on Si 001.– 2=3.Ag produces a uniform compound phase with a 2=2 structure that lacks mirror symmetry in thew110xdirection. Further H adsorption causes agglomeration of surface atoms while the flat area of the surface becomes dominated by another asymmetric 2=2 structure. q1998 Elsevier Science B.V. All rights reserved.