Hi all, Does the error maximize at 2-theta = 90 then decrease again? Back when I was an actual crystallographer and used an INEL system, this was observed when the capillary position was not coaxial with the detector (in fact, when it was behind the proper position).
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:* Kurt Leinenweber [mailto:ku...@asu.edu] > > *Sent:* Thursday, January 08, 2009 6:09 PM > > *To:* Rietveld_l@ill.fr > > *Subject:* error in peak positions that is linear in theta > > > > > > > > Dear Rietvelders, > > > > > > > > (I hope this list is appropriate for this question). I am trying to set > > up a new D8 diffractometer from Bruker, and have it set up with a Vario > > monochromator focusing on a sample in a capillary. Of course I hope to > > do Rietveld refinement on the samples eventually. But there is an error > > in two theta of the peak positions on all samples, and the error is > > linear in two theta. At 40 degrees the error (measured minus expected) > > is about 0.020 degrees, at 80 degrees the error is about 0.040 degrees, > > etcetera. > > > > > > > > Has anyone ever seen anything like this and do you know where it could > > come from? > > > > > > > > Thank you very much, > > > > > > > > - Kurt > > > > > > > > > > > > ********* > > > > Kurt Leinenweber > > > > Dept. of Chemistry and Biochemistry > > > > Arizona State University > > > > Tempe, AZ 85287-1604 > > > > > > > > phone (480)-965-8853 > > > > fax (480)-965-2747 > > > > > > > > *********** > > > > > > >
