Hello,
I believe I have synthesized a good quantity of lithium ethylene dicarbonate salt (LEDC), using a slight variant of the Tarascon method, used by Kang Xu, et al., (Xu, K., Lam, Y., Zhang, S.S., Jow, T.R., Curtis, T.B. J. Phys. Chem. C 2007, 111,
7411-7421)
It is an incredibly fine powder and produced almost no diffractive resolution whatsoever. I confirmed this by shipping it to BM-11 at the APS at Argonne.
I also tried to grow both sing. xtal as well as generate polycrystalline sample, and I believe that I have succeeded. I used the VD, as well as the hot-cold methods.
The issue, it seems, remains a diffractive one. We mounted the sing. xtal in a loop using mineral oil but did not get a diffraction pattern. This appears to leave us with one of two possibilities: 1) it's not a crystal or 2) something silly is going on with either the mounting, positioning or XRD. I suspect it's the latter, b/z under microscopy, it does appear we have grown xtal.
Any help would be greatly appreciated and I direct this question to Dr. Ravi Ananth.
Please provide more details and photos of your XRD setup when convenient. Wave-length, crystal thickness, XRD image detecting tool, beam conditioning, collimation, slits sizes, etc. XRD is the unequivocal in situ method to determine the crystallinity of any material powder or bulk.
BTW where are you physically located? I see, Hunter College, 695 Park Ave, New York, NY 10065 (212) 772-4000 Right? That should be easy to work with. I'm only within a couple of hours from you. http://www.hunter.cuny.edu/main/
This question is of fundamental interest to me. I'm in for the ride! Here is a prerequisite to maximize your Bragg XRD Microscopy experience. A panacea to most information ailments in XRD. A work-book from history that is still valid and applicable. Andre Guinier's classic, "X-ray Diffraction in Crystals, Imperfect Crystals & Amorphous Bodies" 1962. Praphrasing AG - "If you find smoke in reciprocal space then you'll find the cigar in real space". Meaning if your material fits any of the above desriptions including "Crystals, Imperfect Crystals & Amorphous" then you should be able to detect that from the XRD signal. The questiion is, if your XRD detector and technique has the resolution you desire?
http://www.flickr.com/photos/85210325@N04/10515372183/
Stephen! "2) something silly is going on with either the mounting, positioning or XRD. I suspect it's the latter, b/z under microscopy, it does appear we have grown xtal."
This one is easy to eliminate. Put a known crystal in your "loop" and see if the XRD signal appears for it.
If you have doubt about the XRD the best solution could be to use a known reference crystal and check the signal as Ravi suggested. If the XRD passed the test then the problem could be the crystallinity of your sample. You could either have very small crystal size or none.
Related LinkedIn (LI) technical discussion with more details of experiment:
http://www.linkedin.com/groupItem?view=&gid=2683600&item=5835507264106037248&type=member&commentID=discussion%3A5835507264106037248%3Agroup%3A2683600&trk=hb_ntf_COMMENTED_ON_GROUP_DISCUSSION_YOU_CREATED#commentID_discussion%3A5835507264106037248%3Agroup%3A2683600
RG members are all preapproved & prequalified to join our LI group, " X-ray Diffraction Imaging for Materials Microstructural QC"! Please feel welcome to join us and share your knowledge & expertise.
http://www.flickr.com/photos/85210325@N04/10659886546/
Stephen! Please share more about " VD, as well as the hot-cold methods" when convenient. I'm clueless!
http://www.flickr.com/photos/85210325@N04/10221987094/
How stable is your crystalline sample in air? How long does your XRD data acquisition take for a conventional diffractogram? If your crystals are hygroscopic then you need to protect them from the ambient and use a real time in situ 2D XRD method preferably. You may always resort to photographic film to establish feasibility in terms of SNR (signal to noise ratio). Got film? That nearly extinct "power tool" in any XRD lab.
Hatem! I want to see you post on our LinkedIn group noted earlier as well. Join and share in the wealth of knowledge! No scoring or points involved. Just straight talk as it comes to your mind.
Dear Ravi
I did not understand what you mean is there any link to share or participate other than RG
Related LinkedIn (LI) technical discussion with more details of experiment:
http://www.linkedin.com/groupItem?view=&gid=2683600&item=5835507264106037248&type=member&commentID=discussion%3A5835507264106037248%3Agroup%3A2683600&trk=hb_ntf_COMMENTED_ON_GROUP_DISCUSSION_YOU_CREATED#commentID_discussion%3A5835507264106037248%3Agroup%3A2683600
Click, join and contribute at will! No scoring or points involved. Just straight talk as it comes to your mind. The only etiquette we follow is proper attribution for others' words or thoughts we use whenever possible (memory permitting) to avoid the appearance of plagiarism & its associated discomfort/de-edification. We're all friends.
Send me an email [email protected]
http://www.linkedin.com/groupItem?view=&gid=2683600&item=5835507264106037248&type=member&commentID=discussion%3A5835507264106037248%3Agroup%3A2683600&trk=hb_ntf_COMMENTED_ON_GROUP_DISCUSSION_YOU_CREATED#commentID_discussion%3A5835507264106037248%3Agroup%3A2683600
Electron diffraction could represent a solution. Is there a reason for which you have not considered it?
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