Sr2FeMoO6+x:film structure dependence upon substrate type and film thickness

We have prepared a series of Sr2FeMoO6+x films, from 15 to 240 nm thick, on various types of substrates in order to identify associated structure trends. The out-of-plane lattice parameter, c-axis, has been shown to be influenced by the in-plane film-substrate lattice mismatch, and by compositional changes on LaAlO3 and SrTiO3, but not on MgO and Sr0.5Ba0.5TiO3. Surface roughness has been shown to increase with thickness and for films on SrTiO3 peaks due to SrO make the increase stronger. The composition is shown to become Fe rich and Sr and Mo deficient for the films on MgO and LaAlO3 as the film thickness is decreased, whereas on SrTiO3 and Sr0.5Ba0.5TiO3 no significant change is seen. Growth of FeO, SrMoO4 and SrMoO3 phases is seen in several films.