Study of the Si(111)√3 × √3-Ga surface by X-ray photoelectron and auger electron diffraction

Abstract Azimuthal X-ray photoelectron and Auger electron diffraction patterns have been measured for the Si(111)√3 × √3-Ga surface. The diffraction patterns have been excellently reproduced by kinematical calculations for an overlayer model in which one third of a monolayer of Ga atoms are arranged on the √3 × √3 sites of the substrate. This is consistent with the T 4 and H 3 models recently proposed for the Si(111)√3 × √3-Group III metal surfaces. The effect of spherical waves on the diffraction patterns has been examined.