Rutherford backscattering/channeling and transmission electron microscopy analysis of epitaxial BaF2 films on Ge and InP

We have used Rutherford backscattering/channeling and transmission electron microscopy to study the epitaxial growth of BaF2 vacuum deposited onto (100) and (111) surfaces of InP and Ge. We have observed no epitaxy in BaF2 on Ge(100), and only poor quality growth on InP(111). Both the BaF2/InP(100) and BaF2/Ge(111) systems show excellent epitaxy. For these latter two cases the epitaxial quality depends strongly on substrate temperature. Even though a large lattice mismatch exists TEM analysis indicates that for BaF2/Ge(111) neither are there misfit dislocations at the interface nor is the structure coherent.