I want to measure dislocation density in Al by XRD, and have studied some stuff but am not yet clear about how exactly it will work. Can somebody explain this to me with some worked examples?
Positron annihilation (lifetime measurements) is a nice (cheap and fast) technique to measure defects (including dislocations) in solid state.
Cheers
Grzegorz Karwasz, Torun, Poland
Because of the formation of texture during cold rolling, the measurement of dislocation density with XRD is difficult. You can try the method of Ungár, et. al. (http://csendes.elte.hu/cmwp/).
Best Regard
Martin Deutges
There are lots of works concerning the problem of dislocation density determination from diffraction data. Google for classical works of Wilkens, e.g.,"Theoretical aspects of kinematical X-Ray diffraction profiles from crystals containing dislocation distributions" or "The determination of density and distribution of dislocations in deformed single crystals from broadened X‐ray diffraction profiles". Some recent works: http://doi.org/doi:10.1107/S010876730804186X, http://doi.org/doi:10.1107/S0021889899009334. There are lots of useful references in these papers. Concerning software, you may try using a PM2K program: http://www.matteoleoni.ing.unitn.it/html/pm2k.html. Of course, you will need good data collected on good instrument to get reliable results.
Personally, I do not trust XRD methods for determining dislocation density. Positron annihilation, I agree, is good method. X-rays not so much unless you are doing topography on a single crystal.
With ecci do you actually measure the density of line segments in each image?
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