Although my question is addressed to Davor Balzar, I think that the question and the answer may also interest other subscribers of SDPD and RIETVELD lists. The First Phase results of the Size-Strain Round-Robin are really impressive and I wonder, will it be possible to get acquainted with techniques used by the participants and with values obtained? Perhaps this would not be in contradiction with the round-robin strategy if, by authority of the participants, to put their reports in the Internet. This may allow more objective discussion of the results, which will surely contribute both to the analysis of the First Phase and to the 2-nd phase of the round-robin. Following earlier suggestion of Armel Le Bail I have already posted my report in the mailing list. With this letter I have attached it in html format, which can be read by Internet Explorer, Netscape and etc. Leonid Solovyov __________________________________________________ Do You Yahoo!? Get email at your own domain with Yahoo! Mail. http://personal.mail.yahoo.com/Title: ss_rr_leosol
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Size-Strain Round Robin results Method: Rietveld-refinement using Modified Thompson-Cox-Hastings profile function with the Gaussian and Lorentzian FWHM defined as: FWHMG = (Utan2q + Vtanq + Z/cosq2 + W)1/2 FWHML = X tanq + Y/cosq The volume-weighted size is calculated as: Dv = 2Kl cosq-1 / [bL + (bL2 + 4bG2)1/2] = 720Klp-2 / [Ys + (Ys2 + 4Zs/(pln2))1/2] Ys = Yb – Yi; Zs = Zb – Zi where bG and bL are the Gaussian and Lorentzian integral breadths, Yb, Zb and Yi, Zi are the constants for the "Broadened sample" and "Instrumental standard" respectively, K is the Scherrer constant (K=1.0747 for spherical crystallites). Computer Program: Local modification of DBWS Results of CeO2 data analysis
Refined profile parameters for the "Instrumental standard": Xi = 0.0379(8), Yi = 0.0116(7), W = 0.00152(5), U=V=Z=0 R-factors: Rwp = 0.110, Rp = 0.074, RB = 0.012 Refined profile parameters for the "Broadened sample": Xb = 0.080(2), Yb = 0.149(2), Zb = 0.0396(7), W = 0.00152, U=V=0 R-factors: Rwp = 0.069, Rp = 0.050, RB = 0.036 Calculated volume-weighted size Dv = 273 Å Refined profile parameters for the "Instrumental standard": Yi = 0.00346(3), W = 0.000021(1), U=V=Z=X=0 R-factors: Rwp = 0.145, Rp = 0.090, RB = 0.015 Refined profile parameters for the "Broadened sample": Xb = 0.019(2), Yb = 0.0477(3), Zb = 0.00214(4), W = 0.000021, U=V=0 R-factors: Rwp = 0.040, Rp = 0.029, RB = 0.018 Calculated volume-weighted size Dv = 259 Å
Contact address: Leonid A. Solovyov Institute of Chemistry and Chemical Technology K.Marx str. 42 660049, Krasnoyarsk RUSSIAE-mail: [EMAIL PROTECTED]http://krsk.infotel.ru/icct/en/frames.htm http://mesoporous.narod.ru/AboutUs/Solovyov/Solovyov.html |
