A random distribution of 2-dimensional GaAs islands was found to affect the intensity of electron diffraction patterns from the GaAs(001) surface. By utilizing the spontaneous island formation phenomenon, as well as sub-monolayer deposition, the island coverage was systematically changed. It was found that the intensities of the 1-, 2- and 3-quarter order diffraction spots of the [1¯10] azimuth decreased as the concentration of islands increased. In addition, only in the presence of islands did the intensity of the half-order spot decrease as the grazing angle of the electron beam was decreased. A simple quantitative model was developed which provided insight into how an aperiodic arrangement of islands affected electron diffraction patterns.

Role of Aperiodic Surface Defects on the Intensity of Electron Diffraction Spots. D.W.Bullock, Z.Ding, P.M.Thibado, V.P.LaBella: Applied Physics Letters, 2003, 82[16], 2586-8