XRD measurements of 100 nm thick YSZ films on top of 5 nm YSZ films grown in varying pressures. (a) XRD θ − 2θ scans of the films with the first 5 nm grown at a total pressure of 2*10−2 mbar Ar. At 33° a multiple reflection peak of the Si can be observed. The variation in intensity of this peak is only related to the in-plane orientation of the sample in the XRD40. (b) FWHM of the YSZ (002) rocking curves of the samples with the initial 5 nm grown in total pressures of 2*10−2 or 1*10−1 mbar. The dashed lines are inserted for visual reference. (c–f) RHEED images corresponding to the films shown in subfigure a, after growth of 5 nm in respectively 1*10−5, 1*10−4, 5*10−3 and 2*0−2 mbar. The images were taken after adding the 0.02 mbar O2 to the growth chamber for growth of the 100 nm layer. (g–i) RHEED images of the same samples after growth of the 100 nm layer in 0.02 mbar O2. The rings indicated by a green arrow are artefacts formed by reflection of the electron beam at its entrance pinhole to the growth chamber.