Thank you to all for your generous help... has been very important your information..
Mario. 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 >>> >>> >> >> >> >> > > > > >
