Abstract
Alternate layers of GaAs and Ca0.5Sr0.5F2 are grown by molecular beam epitaxy. The morphology, orientation, composition and crystallinity of the layers are analyzed as a function of growth temperature and sequence. The fluoride layers show a high degree of crystallinity and a smooth surface morphology. The structural and morphological quality of the GaAs overlayer is improved by electron irradiation of the fluoride surface prior to GaAs growth, and by a two-step growth procedure for the GaAs over-growth.