So far the only method I've come across for analyzing deliquescent compounds is using an inert atmosphere under Mylar film, which presents its own problems. Are there any other ways to analyze water absorbing crystals such as CaCl2 without drastically changing the XRD set up. BTW, I run an open atmosphere D-500.
Can you use the instrument in capillary mode? Eg, do you have a capillary holder for the instrument? If so you could seal the sample in a glass or kapton capillary. What is your setup within the D-500?
If you use a fast detector, it should be possible to measure your sample under inert oil as used by single-crystal people to select air sensitive crystals under the microscope. Of course, the background will increase somewhat.
We have the capacity for zero background, shallow wells, and surface analysis with a clay mount holder.
The D-500 is using a monochrometer with Ni filter and standard scintillator for detection.
I may be able to get away with an inert atmosphere/oil wrap with the shallow well holder. Any particular inert oil that you'd recommend?
We use a long-chain paraffin oil from Infineum company. Nujol (used for i.r. spectra) should work also. Your problem is that with a standard scintillator counter you have probably long measuring times of an hour or more. I am not sure whether your sample remains unchanged for such a long time under oil, but you could check that by reapeating exposures over a small angle range.
Good idea, I can scan areas of known peaks to check for the material if i know what that it should be there ahead of time. I'll look into the Nujol material too.
Once I had to deal with an extremely corrosive and deliquescent material (NaHSO4).I had to do EPR of Mn-doped NaHSO4. I just applied a thin layer of petroleum jelly(aka Vaseline). It worked. Probably it will work for XRD too.
I used to place a small amount of drying agent at the end of a capillary followed by a retaining plug of glass wool ald then loaded the crystal. The tube was then flame-sealed.
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