ABSTRACT We have grown BaMgF4 films on (111)-oriented Si substrates with existing native oxide layers using molecular beam epitaxy. The early stages of growth were studied through the application of x-ray photoelectron spectroscopy measurements on interrupted growth runs without exposing films to atmosphere. Exposure of the Si substrates to the BaMgF4 vapor at a substrate temperature of 950°C resulted in the formation of silicate species and a reduction of the SiO2 species on the substrate. Subsequent growth onto this silicate buffer layer resulted in highly textured (020)-oriented BaMgF4 films, as evidenced by x-ray diffraction studies.