Davide,
Did you check for extinction and preferred orientation? Otherwise what
does a combined fit give? The difference of about 10 sigma suggests a
remaining systematic error. What is the impact of refining anisotropically?
Good luck,
Jon
Davide Levy wrote:
Dear All,
I have a ”philosophic” question for you: the structure obtained by NPD
are better than the ones found by XRPD?
I explain a little bit more my question, I studied a MgAlFeO4 spinel
both by NDP and XRPD from RT to 1000°C. The O coordinate it is
different for two data set (0.2581 vs.0.25953). The found error on the
oxygen coordinate is about 10^-5 and 10^-4 for NPD and XRPD data
respectively. The coordinate calculated from cation partitioning and
cation radii is similar to the XRPD result.
At the moment I did not found a justification of this and I do not
know which result is the ‘right one’.
Do you have any suggestion?
Thank you
Davide
