Hi,
I really wonder why do you bother about 1% difference when the error of
the method (XRD, quantitative phase analysis) could reach 10%
(absolute) ...
People in the discussions appearing here seem to forget about two things:
i) "quantitative" phase analysis done by rietveld method is always
Periclase is really problematic because of the small number of peaks in
the usual angular range used for QPA with Cu or Co radiation. Thus, the
particle statistics problem becomes extremely critic, as Pamela already
said. The uncertainties can be compared with the statistical intensity
errors o
Which background function is suitable for Rietveld refinement using the
program MAUD? Is it polynomial or the interpolated function? And which
parameters determine the zero shift?
With regards
Soumen Ghosh
Department of Physics
Jadavpur University
Kolkata-700032, India
--
Which background function is suitable for Rietveld refinement using the program
MAUD? Is it polynomial or the interpolated function? And which parameters
determine the zero shift?
With regards
Soumen Ghosh
Department of Physics
Jadavpur University
Kolkata-700032, India
I'm afraid that 30 microns might be small to the eye but is too big for quant
analysis. The particles need to be in the range of a micron or two. There's
an old paper by Deane Smith that did a brilliant job of showing the effects in
a statistical manner.
Pam
From: José Carlos Cordeiro
My samples are cements (fine samples with 30 microns) and don't need micronize
its. The problem in my refinements is that periclase quantified with fixed slit
is bigger than MgO by Fluorescence, and its impossible. Ex:
Periclase with fixed slit: 7,14%
MgO by XRF = 6,84%
We know that part
Hi Jose
Errors in the region of 1wt% aren't unheard of in complex mixtures (and the
liklihood of the second decimal place being meaningful is very slim). However
there are other possible explanations and one in particular comes to mind.
Did you micronize your sample? If yes then feel free to
I have a Programmable Divergence Slit (incident beam) in my difratctometer,
that can work in automatic mode (irradiated length) or fixed mode (0.5 degree
or 1.0 degree etc). What is the best collect mode for Rietveld Refinament??
I did refinement two difractograms collected in booth configura
