It would be useful to have more details. Certain types of materials may be tricky to refine if your measurement range extends beyond where you can visibly see distinct peaks. At higher angles you might have a majority of low intensity overlapping peaks (exacerbated by the addition of an internal standard). This can lead to high eta values if you are not careful. Proper fitting of all peak shape parameters requires good data at higher angles. If this is the case I would try trimming your data range and/or setting some of your peak parameters to "reasonable" values (what is "reasonable" ???). Maybe only refine u and keep v and w at zero (if you are using that kind of profile function). Conversely, the choice of internal standard is important too. Is the lowest angle peak of the standard underfitted while higher angle peaks are overfitted? This would point to a problem with either the measurement setup or the standard material.
Some simple ideas to verify the results: Try the spiking method (vary the proportion of standard and sample and see if results are the same) or the external standard method (if you know the composition of both sample and standard). Jeff Nicolich On Wed, Mar 3, 2021 at 12:36 PM François Goutenoire < [email protected]> wrote: > Dear Rietveld users, > > I have some industrial compound presenting a strong hyper-Lorentzian peak > shape (eta=1.1 with HighScore). When we calculate the amorphous content > after an internal standard addition, the result is 40%. The > micro-absorption effect has been minimized (mu of the internal standard is > closed to the compound). > > But with some electronic transmission analysis no amorphous is observed. > > The question is : Does a strong hyper-Lorentzian peak shape could > influence quantitative analysis ? > > François > > -- > > ********************************************************************************************* > Pr. Francois GOUTENOIRE > e-mail: [email protected] > Tel: 02.43.83.33.54 > FAX: 02.43.83.35.06 > Skype Entreprise visio conférence > Département des Oxydes et Fluorures > Institut des Molécules et des Matériaux du Mans > IMMM - UMR CNRS 6283 > Université du Maine - Avenue Olivier Messiaen > F-72085 Le Mans Cedex 9 > FRANCE > > ********************************************************************************************* > Formation Rietveld CNRS 2020 > > https://cnrsformation.cnrs.fr/diffraction-des-rayons-x-sur-materiaux-polycristallins?axe=135 > Formation EDX CNRS 2020 > https://cnrsformation.cnrs.fr/fluorescence-x-edx?axe=135 > Formation SAXS et Réflectivités pour couches minces et matériaux > nanostructurés. > > https://cnrsformation.cnrs.fr/caracterisation-des-materiaux-nanostructures-par-diffusion-des-rayons-x?axe=135 > Bibliographie > > https://scholar.google.fr/citations?hl=fr&user=qC-lmN4AAAAJ&view_op=list_works&authuser=1&sortby=title > https://orcid.org/0000-0001-5339-3002 > > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > Please do NOT attach files to the whole list <[email protected] > > > Send commands to <[email protected]> eg: HELP as the subject with no body > text > The Rietveld_L list archive is on > http://www.mail-archive.com/[email protected]/ > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > >
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Please do NOT attach files to the whole list <[email protected]> Send commands to <[email protected]> eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/[email protected]/ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
