Dear All:
Recently we performed some measurements using a MAR345 detector. As we knew
the ambient temperature and pressure lattice constants for the sample, we
used this information for the sample to image plate and tilt correction
calibration in FIT2D. We then used this sample to plate and tilt
information to perform an integration of the same image that was used for
the calibration. If we take the integrated data and perform a LeBail fit in
GSAS we can not get a good fit to the data without introducing a zero shift
(this does not make sense to me). Additionally, after refining the zero
shift, the lattice constant that we get back is different from that used in
the original calibration! Essentially the peak positions in the integrated
data do not agree with the peak positions that were used in the
calibration. Any ideas as to what might be going wrong?
Thanks in advance, Angus
Dr. Angus P. Wilkinson School of Chemistry and
Biochemistry
Prof. Chemistry and Biochemistry Georgia Institute
of Technology
Prof. Materials Science and Engineering 770 State St.
Atlanta, GA 30332-0400
Tel: 404 894 4036
Fax: 404 894 7452
