  A detailed reflection high-energy electron diffraction analysis shows
relevant features of the lattice parameter relaxation of CdSe thin films grown
in a layer-by-layer mode onto ZnSe. In situ investigations of different
azimuths show a clear lattice parameter oscillation in the 110 azimuth. The
lattice parameter has a minimum value ~similar to that of ZnSe! during Se
exposure steps, and a higher and increasing lattice parameter during Cd
exposure steps. The behavior is ascribed to the formation of CdSe islands
during Cd exposure steps. The cumulative effect in CdSe exposure steps is
considered to be a consequence of a decrease in the island size with the number
of cycles. Actual plastic deformation does occur after 5 ML.
