Dear Lee: This is interesting to me.
Before i take some comments, would you like to send me your data and give me a chance to try. i hope you have done the Rietveld refinement using GSAS. If so, can you send me a package including: 1) recent .exp file; 2) the three .cif file for A, B and corundum. 3) the .ins file describing your instrument parameters. and 4) the GSAS raw data file. If not, please simply send me the upmentioned information without GSAS related format. Faithfully Jun Lu ---------- Lst. Prof. Lijie Qiao Department of Materials Physics and Chemistry University of Science and Technology Beijing 100083 Beijing P.R. China http://www.instrument.com.cn/ilog/handsomeland/ Lst. Prof. Loidl and Lunkenheimer Experimental Physics V Center for Electronic Correlations and Magnetism (EKM) University of Augsburg Universitaetsstr. 2 86159 Augsburg Germany http://www.physik.uni-augsburg.de/exp5 ----- Original Message ----- From: "Lee Gerrard" <[EMAIL PROTECTED]> To: <rietveld_l@ill.fr> Sent: Tuesday, October 14, 2008 2:20 PM Subject: Question on QPA - Amorphous/crystalline mix >I have a question for the list as I know there are a number of people > working on QPA. Ok the question is as follows:- > > We have a mixture of a number of crystalline phases (A and B) and an > amorphous (glassy) phase. We can do Rietveld refinement on this and get > weight percentage (wt.%) values for the crystalline components. We have > added a known amount of corundum as a standard and refined again. > Example values we get are as follows:- > > Phase A 10 wt.% > Phase B 50 wt.% > Corundum 40 wt.% > > BUT we know we have added only 33 wt.% corundum - are we able to > calculate the wt.% of the amorphous content from the known values? I > have tried scaling/ratio'ing the values to the known corundum amount > therefore giving:- > > Phase A 8.25 % > Phase B 41.25 % > Corundum 33 % > > TOTAL 82.5 % > > which leaves 17.5 % left over. Hence must be the amorphous part?? > > I am not totally convinced by this method at all and would love to know > how is best to go about solving this problem. > > Many thanks, > > Lee > ~~~~~~~~~~~~~~~~~~~~~~~~~~~ > Dr. Lee A. Gerrard BSc CChem CSci MRSC > Materials Scientist > > Materials Science Research Division > SB40.1 > AWE Plc > Aldermaston, Reading, > Berkshire > RG7 4PR > > Tel: +44 (0)118 982 6516 > Fax: +44 (0)118 982 4739 > Email: [EMAIL PROTECTED] > ~~~~~~~~~~~~~~~~~~~~~~~~~~~ > >
