As one can read in numerous papers on this matter, the dislocation density is derived from the dependence of peak broadening on the diffraction angle, that is, on considered reflections. Thus, to get tractable data, it is enough to vary positions of the source and detector while keeping the specimen immobile. However, although the result will certainly depend on the texture, I have never seen any analysis of such a delicate issue. This is very strange indeed since the increase of dislocation density undoubtedly correlates with the evolution of deformation texture!!
It still should be noted that the problem is SOMETMIES addressed as follows for examples.
Borbely, Driver, Archive of Metall. And Mater., V50 (2005).
Sousa et al, Mater. Res. V18 (2015).
Joni et al, Crystals, V10 (2020) .
Nonetheless I insist: the significant texture-related uncertainty of estimated dislocation density MUST be properly reflected in practice.
This is perhaps because some of the most polpular XRD techniques like Debye-Scherrer Powder method effectivelt averages out all directional data, so texture information is lost, whereas overall peak brodening is not (and that broadening can be accounted for grain, subgrain, dislocation size, and of course, instrument). Single-crystal diffraction techniques like Laue is essentially discrete, whereas texturing of dislocation density might be continous, so dislocation density from single crystal is not usually reported. For static specimen and cyllindrical detector XRD (I forgot its name!) there is still that discrete issue. While there can be texture-dislocation analysis possible in this technique, I have not yet come across such techniques. Other techniques partly based on XRD or similar principles but often not regarded as true XRD per-se e.g. EBSD does provide texture data.
I mean that texture CAN BE allowed for but this option is ignored. Most probably to avoid cumbersome simultaneous variations of reflections and specimen orientations, I believe the texture related errors may be excluded by an appropriate technique of neutron diffraction where ALL orientations are readily registered.
Please, check out the papers by Perlovich, Isaenkova et al, who attempted to account for crystallographic texture to characterize the related heterogeneity in structural parameters evaluated by XRD analysis:
Article Determination of Grain Size for Different Texture Components...
Article Distributions of Domain Size, Lattice Distortion and Disloca...
and so on
Thanks for an intersting (second) matter. As Isupposed, they repeated the analysis of reflections (peak broadening) at varying sample orienttions (texture components).
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