Broad peaks... could the Y2O3 need to be annealed? - Kurt ________________________________
From: Leonid Solovyov [mailto:[EMAIL PROTECTED] Sent: Fri 12/5/2008 8:14 AM To: rietveld_l@ill.fr Subject: Re: Can anybody do me a favor to refine my Y2O3? Dear Li, I don't use GSAS, but I refined your data using the DDM program that gave nearly perfect fit. The DDM parameters file is attached and the program is freely available from http://www.icct.ru/eng/content/persons/Sol_LA/ddm.html or http://www.geocities.com/l_solovyov/ddm.html I must note, however, that the diffraction peaks in your pattern are very broad which may indicate a misalignment of your instrument or some problems with the X-ray tube. For this setup of X'Pert MPD the width of peaks below 60 degrees 2theta should be less that 0.1, but your width is around 0.3 - too big! Best regards, Leonid ******************************************************* Leonid A. Solovyov Institute of Chemistry and Chemical Technology 660049, K. Marx 42, Krasnoyarsk, Russia www.icct.ru/eng/content/persons/Sol_LA www.geocities.com/l_solovyov ******************************************************* --- On Fri, 12/5/08, Mingtao Li <[EMAIL PROTECTED]> wrote: > From: Mingtao Li <[EMAIL PROTECTED]> > Subject: Can anybody do me a favor to refine my Y2O3? > To: "Rietveld_l" <rietveld_l@ill.fr> > Date: Friday, December 5, 2008, 2:07 PM > To all, > I am learning rietveld refinement. First I want to > get my > instrumental parameter file. So I collected xrd pattern of > cubic Y2O3 > on a X'pert pro MPD diffractiometer. The experimental > conditions were > listed as following: > > Cu KAlpha: > KAlpha1:1.5405980 > KAlpha2:1.5444260 > ratio KAlpha2/KAlpha1:0.5000 > > Incidental Beam Path: > soller slit:0.02rad > divergence slit 1 degree > anti-scatter slit 2 degree > incidental mask 10 mm > > Goniometer Radius 240mm > > Diffracted Beam Path > antiScatterSlit: AS Slit 6.6mm > sollerSlit:0.02rad > filter:nickel (thickness:0.02mm) > Detector:X'Celerator > > The xrdml attached is the original pattern file. The cif > file of cubic > Y2O3 and gsa file of the pattern are also attached. > > I have tried to do the refinement using GSAS many times > following the > instructions from http://www.cins.ca/cpdw/notes.html., but > the results > were quite different every time, especially the unit cell. > Now I am > very confused. Why did that happen? Shouldn't I refine > S/L and H/L? So > here I am for help. Can anyone do me a favor to refine my > Y2O3 give a > "standard" result? > > Thanks in advance. > > -- > ********************************************************************** > Mingtao Li, Ph.D. Candidate > State Key Laboratory of Multiphase Flow in Power > Engineering > School of Energy and Power Engineering, Xi'an Jiaotong > University > No.28, Xianning West Road, Xi'an, Shaanxi, 710049, P.R. > China > Tel: +86-29-82668296-11 Fax: > +86-29-82669033 > E-mail: mingtao dot li at gmail dot com > **********************************************************************
