To investigate the changes in atomic-scale structure associated with deformation, can I do in-situ high energy X-ray diffraction when compression conducted at cryogenic temperatures (below 200 K)?
Yes and no. All depends on your limits to the sample environment. Gas pressure cells with two X-ray transparent windows and good cooling (e.g. cold finger) can do the job with little effort. You can do similar tricks with diamond anvil cells and a cryojet but the T control is questionable. For the mechanical loading like in the Paris-Edinburg press you may loose much flux due to the absorption but hard X-rays should go through. I would advice to go for some material science beamline at one of the synchrotron rings. Lab sources even with Ag or W targets will be most likely inadequate for the in-situ work if you attempt to investigate dynamic processes.
Dear Andrzej Falenty, thank you very much. Yes, you are right, high energy synchrotron source may facilitate such experiments, and we also think so. If it is feasible, we can do in-situ compression test at cryogenic temperatures, right? So, how about the sample size? Micropillar or nanopillar? And do you think some artifacts would influence the data collection?
Simple Andrzej is really enough :). All material science beamlines that I know have a transmission, Debye Scherrer geometry so the sample size will be defined by its attenuation plus the attenuation from the environmental cell. Please check the attenuation coefficients of all solids and liquids and heavy gasses on the X-ray path. From that you can safely estimate how much flux you loose. If your goal is diffraction then in the refinement you may need to add also a parameter that deals with absorption and potentially sample position.
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