Elastic Constants and X-Ray Stress Measurement of Cubic Thin Films with Fiber Texture

Abstract

A new X-ray method is proposed to measure the residual stress in cubic polycrystalline films having the fiber texture with the axis of<111> <100>and<100>perpendicular to the film surface. The elastic constants of textured thin films were calculated on the bases of Reuss and Voigt models. According to the analysis based on Reuss model, the relation between the strain measured by X-ray, ε^^-L_<33> and sin² ψ for the equi-biaxial stress is linear for the cases of<111>and<100>fiber textures. For the other cases, the relation is non-linear. A method to determine the stress from non-linear relations is proposed. The analysis based on Voigt model gives the linear relation between ε^^-L_<33> and sin² ψ for any case of fiber texture. In thin films made of materials with low anisotroy, the both models give nearly identical relation.