sorry to blame you with this (I tend to be messy on my real-life desktop,
but I am not sure, whether or not I ever had a paper on this topic):
I did some neutron-experiments at Berlin (BER-II, E2,
Debye-Scherrer-Geometry) about a month ago and I do not arrive at good
R-values with my relatively succesfull (all R's around 10-15 %) XRD
structure model. Most probably I do face an absorption problem (intensities
of the front part of the pattern are calculated with far too high values)
and I was not yet able to find a reference or a hint how to perform the
absorption correction mentioned within the FullProf manual.
Carvajal says therein, the software would correct the intensities by a
function demanding a non-refinable value "mR" where m is the linear
absorption coefficient and R the radius of the cylindrical sample.
My question(s):
- How can I determine "m"? Are there tables, references?
- Allthough I know how to determine "R" (anyway - thanks for hints ...
haha), what is the dimension demanded: m, mm, cm, inches ?
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Talking about absorption - I do face a microabsorption effect in my latestXRD samples, too (taken on a Bragg-Brentano-Machine). Is there anyone withexperiences in REFINING the Pitschle-Mettern-Hermann paramters P0, Cp, Tau(I tried, but I am out of the "good-values-zone" within a cylce or two,usually) out there? Help would be very much appreciated !!
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Thanks for your numerous replies in advance! If you think this is standardstuff, don't bother the others and send your reply directly to me:schinzer@icmcb.u-bordeaux.fr
Thanxalot again
Carsten
Carsten Schinzer ---------------------------------------
Institut de Chimie de la Matiere Condensee de Bordeaux 87, Avenue du Docteur A. Schweitzer F-33608 PESSAC fon +33 556 84 2650 (poste 7397) fax +33 556 84 2640--------------------------------------------------------