Jae-Ho, A while ago I worked on Delafossites (sounds like what you are working on as well). A further question is whether your peaks have reasonable shapes or do they look slightly strange. If the latter, you're probably encountering the effect of stacking faults...
Alex Y ________________________________________ Dr. Alexandre (Alex) F. T. Yokochi Assistant Professor Department of Chemical Engineering Oregon State University Corvallis, OR 97331-2702 Voice: (541) 737-9357 Fax: (541) 737-4600 http://oregonstate.edu/~yokochia > -----Original Message----- > From: Jae-Ho Chung [mailto:[EMAIL PROTECTED] > Sent: Wednesday, February 14, 2007 8:01 AM > To: [email protected] > Subject: Strange peak positions > > Dear all, > > I would appreciate any comments for the following problem. > > I have been studying samples (ABO2) with a rather simple R -3 m structure. > Although I had expected their neutron powder diffraction refinement should > be > simple, I encountered a strange problem. Many of the peak positions are > quite > off from where they should be. For instance, I singled out and refine (0 0 > 3), > (0 0 6), (0 0 9) & (0 0 12) separately. Quite strangely, (0 0 6) peak is > noticeably off when (0 0 3), (0 0 9) and (0 0 12) are good. For full > refinements, such problem shows up for several peaks. I see same trend > from > data measured at two different instruments: CW and TOF. FYI, the peak > profiles > are quite Lorentzian and asymmetric. > > Anybody have experiences such a problem, and/or have suggestions what is > going > on? I would greatly appreciate. > > Jae-Ho > > ************************************* > Jae-Ho Chung, Ph.D. > NIST Center for Neutron Research > 100 Bureau Drive, Stop 8562 > Gaithersburg, MD 20899-8562 > Tel. 301-975-8369 (office) > 301-975-5085 (SPINS) > 240-506-8389 (cell) > Fax. 301-921-9847 > e-mail: [EMAIL PROTECTED] (work) > [EMAIL PROTECTED](personal) > *************************************
