Mario, >From the information that you just gave, it appears that the corundum 012 and >siderite 012 are not well resolved causing more of the siderite 012 intensity >to be attributed to the corundum 012 and an overestimation of corundum. If it >is a microabsorption problem, you wouldn't get a good QPA data without PO >correction to start with. If you can, reduce the receiving slit size and run >the sample again or don't correct for PO.
Dipo Omotoso -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: October 28, 2008 8:24 AM To: Rietveld_l@ill.fr Subject: RE: Quantitative analysis >Dear all, the well-known data are: CaCO3 (20%), CaF2 (35%), SiO2 (1%), Al2O3 (20%), and FeCO3 (24%). The data obtained without PO are: CaCO3 (24%), CaF2 (36%), SiO2 (1%), Al2O3 (17%), and FeCO3 (23%). The data obtained with PO are: CaCO3 (19%), CaF2 (32%), SiO2 (2%), Al2O3 (31%), and FeCO3 (16%). it seems to have a problem among Al2O3 and FeCO3 data after PO. Mario. Dear all, > > The data collection conditions is: hand grind (35 microns), scan: > 2Theta/Theta Coupled, to steps 2 sec., target Cu, graphite > monochromator, side loading. The correction of preferential > orientation has been refined by March-Dollase model. > > Thanks a lot, > > Mario. > > > > > Dear Mario, >> >> Please tell me a little about the data collection conditions you used >> for this work:- >> >> How was the sample prepared (hand ground, micronised in McCrone mill >> ????) >> What was the tube target Cu, Co, other ?? >> >> Cheers >> Ian Madsen >> ________________________________________ >> From: [EMAIL PROTECTED] [EMAIL PROTECTED] >> Sent: Tuesday, October 28, 2008 2:48 AM >> To: Rietveld_l@ill.fr >> Subject: Quantitative analysis >> >> Dear all, >> >> I have this question, >> >> I have been refined one mixture (of well-know percentage composition) >> of CaCO3, CaF2, SiO2 and Al2O3, with preferential orientation in >> CaCO3 >> (104) >> and CaF2 (111) with good results. When I add to the mixture FeCO3 and >> I refine with preferential orientation (104), it happens that when I >> don´t apply the preferential orientation in all this phases, I have >> correct values of percentage composition, but when I apply the >> preferential orientation the refinement is good but with incorrect >> values of percentage composition. This experiment has been taken in >> Bragg Brentano geometry. >> How I should refine this mixture? >> >> Thanks a lot by your help. >> >> Mario Macías >> Universidad Industrial de Santander >> Colombia >> >> > > > >
