The determination of lattice parameters and strains in stressed thin films using X-ray diffraction with Seeman-Bohlin focusing

Routes to Probe Strain in “ZnO/ZnS Superlattice” Nanostructures by X-ray Diffraction

“…The biaxial strain model has been widely used to study the in-plane strains at the film/substrate and heterostructures interfaces . It can be decomposed into a sum of a uniaxial and a hydrostatic strain component, both of them being important tunable parameters in the strain-induced band gap engineering and having significant effects on the band structures. − For the textured or single crystalline-like films, the needed diffraction peaks are difficult to observe in the standard Bragg–Brentano geometry, so many other modified sin 2 ψ methods and the grazing-incidence XRD techniques have been developed to overcome these problems. − If the triaxial strains or the strain gradients along the surface normal present in the samples, the relationship between the strain along the diffraction direction ε φψ and sin 2 ψ will violate the linear variation, and the biaxial strain model may fail to describe these situations, such as the observed oscillatory ε φψ –sin 2 ψ curve caused by the crystallographic texture and the curvature-dependent ε φψ –sin 2 ψ curve resulting from the strain gradients normal to the surface. Many mathematical analysis methods have been developed to quantify and classify these inhomogeneous strains within the sample. ,, For a thorough review of strain/stress analysis by XRD, we refer to the works by I. C. Noyan et al and U. Welzel et al…”

Experimental and Theoretical Investigation on Phase Formation and Mechanical Properties in Cr–Co–Ni Alloys Processed Using a Novel Thin-Film Quenching Technique

“…However, the temperature-corrected DFT calculations for 298 K are in good agreement with those reported in the literature as well as the data for bulk alloys. The fact that the lattice parameters obtained in the thin films are systematically lower than in the bulk (both this study and literature) is assumed to be an effect of stresses due to the mismatch of thermal expansion coefficients between the substrate and the deposited thin film and/or the small grain size , of the thin films. While the addition of Co to Ni results in a slight increase of the lattice parameter, Cr shows a much stronger effect.…”

Instrumental aspects in X-ray diffraction on polycrystalline materials

“…At the beginning of the 1990s several authors (Haase, 1985; Valvoda et al , 1990; Ligen et al , 1994; Fisher and Oettel, 1996) proposed to use the SB arrangement in order to analyze polycrystalline thin films. The main difficulty in the characterization of randomly oriented thin films is to obtain, despite the small amount of matter, patterns with sufficient quality to allow at least conventional exploitation of the diffraction data (i.e., the evaluation of peak position and intensity).…”