What information we can get from PXRD analysis other than from SCXRD analysis of a crystal ?
Hello Mayank Shukla.
Indeed if Single Crystal was already made, then the structure is elucidated. Just to make it clear, single crystal and powder xrd are different analysis, made by different equipments, for different kind of samples. If you manage to grow a single crystal, which is difficult and takes a lot of time, you use SCXRD. If you can't grow a sigle crystal, you go for powder xrd. The results are shown differently, but the structure of a single crystal and a powder of the same material is the same. I do not see the point to crush the single crystal to obtain a powder, once you have already determined the structure. I am no expert in SCXRD, so I can't fully understand why one should do it. Where did you hear this from?
Powder diffraction or diffraction on polycrystalline assemblies allows investigating material in its quite original context. This can give representative diffraction information on the material under consideration, while a single crystal may be very special as compared to your material you obtain your single crystal from. Your question, however, concerned crushing a single crystal (or crystals). This might make sense (additional to the single crystal analysis, which you should try anyway) under certain circumstances. One example is that you might be interesting in precise lattice parameters or info on distortion away from some ideal metric. At least when it comes to standard procedures, powder diffraction equipment provides a very good resolution on the 2theta/d spacing scale, which is often not that excellent in single-crystal diffraction. This of course requires that the crushing of the single crystal does not introduce too many defects affecting the diffraction pattern....
I did that once, crushed up some crystals for someone to do power XRD. The reason they wanted me to do that was to obtain accurate cell constants for a crystal that may have had some dopants in it that could change the constants, and PXRD was a fast and accurate way to do that.
Especially, it gives you the answer if the bulk material complies with the structure solved from one single crystal. This is my personal experience. Sometimes it happens that the measured crystal does not represent the phase composition of the powder.
- Badges
- Science topic
- Similar topics
- Filing