Characterization of defect structures in nanocrystalline materials by X-ray line profile analysis

Abstract

Abstract. X-ray line profile analysis is a powerful alternative tool for determining dislocation densities, dislocation type, crystallite and subgrain size and size-distributions, and planar defects, especially the frequency of twin boundaries and stacking faults. The method is especially useful in the case of submicron grain size or nanocrystalline materials, where X-ray line broadening is a well pronounced effect, and the observation of defects with very large density is often not easy by transmission electron microscopy. The fundamentals of X-ray line broadening are summarized in terms of the different qualitative breadth methods, and the more sophisticated and more quantitative whole pattern fitting procedures. The efficiency and practical use of X-ray line profile analysis is shown by discussing its applications to metallic, ceramic, diamond-like and polymer nanomaterials.

Assessment of Dislocation Density by Various Techniques in Cold Rolled 1050 Aluminum Alloy

“…The development of microstructural features at different length scales was examined through X-ray diffraction, EBSD and indentation techniques. First, the investigated materials were exposed to X-ray diffraction line profile analysis, which allows the dislocation density to be calculated by analyzing the broadening of diffraction lines by the method described in great detail in [6,8]. Both annealed and deformed samples were studied on the plane perpendicular to the normal direction (ND plane).…”

“…Typically, the number of one-dimensional defects is determined using transmission electron microscopy (TEM), which provides a direct image of the substructure that has evolved. As an alternative to TEM, the quantity of dislocations can also be evaluated indirectly by X-ray diffraction line profile analysis (XLPA) [6][7][8], indentation techniques [9] or electron backscattering diffraction (EBSD) [10]. In XLPA, the data are obtained in the form of diffraction lines and the parameters of the defect structure are extracted by analyzing the width and shape of the diffraction peak profiles [6][7][8].…”

“…As an alternative to TEM, the quantity of dislocations can also be evaluated indirectly by X-ray diffraction line profile analysis (XLPA) [6][7][8], indentation techniques [9] or electron backscattering diffraction (EBSD) [10]. In XLPA, the data are obtained in the form of diffraction lines and the parameters of the defect structure are extracted by analyzing the width and shape of the diffraction peak profiles [6][7][8]. The advantages of XLPA over TEM are related to the field of view (bulk in XLPA and very local in TEM) and the possibility of choosing any arbitrary area.…”

Characterization of Defect Structure in Electrodeposited Nanocrystalline Ni Films

“…It has been shown that the break of coherency can occur even for dipolar dislocation walls, although they do not cause any misorientations between the domains [47]. Since the lattice defects fragment the grains into smaller coherently scattering domains, the crystallite size determined by XRD line profile analysis is usually smaller than the grain size obtained by TEM [48]. This difference depends on the processing method of the studied material.…”

An investigation on the microstructure and defects in the mechanically milled Cu and Fe powders

“…The sample preparation is simple and the obtained characteristics are average of the entire sample. These can be empirical advantages over the powerful technique of transmission electron microscopy (TEM) (Tian and Atzmon, 1999; Gubicza and Ungar, 2007). Therefore, several XRD analysis methods have been developed to calculate the crystallite size, microstrain, or dislocation density in different lattice structures.…”