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Abstract: TiN films were prepared by ion beam assisted deposition (IBAD) method under different temperatures and ion energies. Microstructure characterization by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning and transmission electron microscopy (SEM and TEM) confirmed that the nitride films were nanocrystalline in size and composed of grains with grain sizes ∼20 nm. Textures of the films were studied by XRD pole figure measurements. Residual stress was determined by the modified sin2 ψ method using grazing incidence XRD. Hardness of the thin films was measured by nanoindentation. It is found that nanoindentation measurement cannot reflect the variation of residual stress. Nanohardness of the samples also displayed insignificant relationship with texture. Since the dislocation activity is retarded due to nanograin structure, the geometrical strengthening via texture control or Hall–Petch relationship is no longer applicable. Therefore, grain rotation or grain boundary sliding may be the deformation mechanisms for nanocrystalline thin film. The contradictory relationships between hardness and preferred orientation were also clarified. [Copyright &y& Elsevier]

Measurements of residual stresses in textured thin films have always been problematic. In this article, a new experimental method using grazing-incidence X-ray diffraction is presented with its principles based upon the conventional sin2ψ method. Instead of using the Bragg–Brentano (B-B) or Seemann–Bohlin geometry, the proposed method utilizes an asymmetrical diffraction geometry for which the X-ray beam is incident at a grazing angle γ to the sample surface, while the angle ψ is the tilt angle of the sample surface as defined by the conventional sin2ψ method. Basic equations involved in the X-ray residual stress analysis are described, along with exemplified experimental data. Analysis shows that, for an isotropic medium, strain measured using this grazing-incidence geometry assumes a linear relationship with the geometrical parameter cos2α sin2ψ, where the angle α is a constant and is defined as the Bragg angle at ψ=0°, θo, minus the grazing incidence angle γ, i.e. α=θo−γ. The grazing-incidence diffraction geometry effectively increases the irradiation volume from a thin-film specimen, thereby giving rise to higher intensity for high-angle Bragg peaks than the conventional B-B geometry. The proposed analysis has another advantage, in that the inhomogeneous sample casts little effect on the residual stress results when compared to the traditional sin2ψ method. [Copyright &y& Elsevier]