X-RAY PHOTOELECTRON DIFFRACTION STUDY OF YBAS/GAAS(001) AND SCAS/GAAS(001)HETEROSTRUCTURES

Polar angle distributions of core level photoemission intensities recorded on YbAs/GaAs(001) and ScAs/GaAs(001) heterostructures are presented. They allow first the surface roughness of thin YbAs overlayers to be seen, second to estimate the tetragonal distortion of a strained ScAs film and, third, the most interesting point, to demonstrate in a direct fashion that the mixed (Yb‐As) (010) planes of YbAs grow in the prolongation of the As planes of GaAs. The results are compared to those obtained by other authors with various techniques. The main advantage of the photoelectron diffraction method over the other techniques is that it can be performed on very thin epitaxial films (some monolayers) directly in situ under ultrahigh vacuum.