X-ray elastic constants determined by the combination of sin2ψ and substrate-curvature methods

Abstract

Abstract A new methodology is presented that allows the quantification of experimental X-ray elastic constants of polycrystalline thin films without use of special diffractometer attachments. The approach is based on the combination of sin2 ψ and curvature methods. The elastic strains in the polycrystalline films are characterized by the measurement of lattice spacings at different sample tilt angles, while the macroscopic stress in the film is calculated from the substrate curvature applying the Stoney formula. The radius of the curvature is determined from a sequence of rocking curves measured at different sample positions. The method is demonstrated on Al thin films deposited on Si(100) substrates. The X-ray diffraction measurements were performed at the synchrotron source BESSY in Berlin.