  We demonstrate the growth of Co-doped BaFe2As2 (Ba-122) thin films on AEF2
(001) (AE: Ca, Sr, Ba) single crystal substrates using pulsed laser deposition.
All films are grown epitaxially despite of a large misfit of -10.6% for BaF2
substrate. For all films a reaction layer is formed at the interface confirmed
by X-ray diffraction and by transmission electron microscopy. The
superconducting transition temperature of the film on CaF2 is around 27 K,
whereas the corresponding values of the other films are around 21 K. The Ba-122
on CaF2 shows identical crystalline quality and superconducting properties as
films on Fe-buffered MgO.
