Thin films were deposited onto (001)SrTiO3 substrates by sol-gel spin coating. A previous study had shown that the film crystallized with the c-axis normal to the surface. Those epitaxial films were studied by means of X-ray diffraction line profile analysis as a function of thermal annealing duration. The line profile analysis of the diffraction patterns collected in ω-2θ scan mode, gave detailed information on the coherently diffracting domain size and micro-strains along a given direction. For low annealing times, the width of the (001) diffraction lines reached values of about 1°. In accord with a recent study, integral breadth and Fourier analyses suggested the presence of stacking faults which were separated by a mean distance of 5nm. The profiles exhibited a marked Lorentzian character; as expected for a faulted crystal. In addition to faulting, finite grain sizes and micro-strains contributed to the observed width. When the heat treatment time was increased, the breadth and Lorentzian content of the (001) diffraction lines decreased; showing that the stacking fault density had decreased. After 500h at 700C, the calculated domain size equalled the film thickness. This indicated that the stacking faults had almost disappeared.

X-ray Diffraction Line Broadening by Stacking Faults in SrBi2Nb2O9/SrTiO3 Epitaxial Thin Films. A.Boulle, C.Legrand, R.Guinebretière, J.P.Mercurio, A.Dauger: Thin Solid Films, 2001, 391[1], 42-6