[EMAIL PROTECTED] a écrit :
Hi Blaise
In Bragg-Brentano mode, sample spinning does nothin for PO. This is
because the diffraction vector is normal to the sample surface, and
sample spinning rotates along this vector.
That's wrong! As I have already written, the empirical PO corrections
like March-Dollase and Rietveld-Toraya suppose that the PO is fibre-like
(axial symmetry). If your sample does not have fibre-like PO, you can
create it by sample spinning.
Radovan
Spinning does increase your particle statistics, which almost always helps.
If you're looking at a capillary, spinning the capillary does help with
PO, but just being in a capillary helps PO.
As to spinning speeds, a good guide is one revolution per data point.
Cheers
Matthew
________________
Matthew Rowles
CSIRO Minerals
Box 312
Clayton South, Victoria
AUSTRALIA 3169
Ph: +61 3 9545 8892
Fax: +61 3 9562 8919 (site)
Email: [EMAIL PROTECTED]
--
Radovan Cerny
Laboratoire de Cristallographie
24, quai Ernest-Ansermet
CH-1211 Geneva 4, Switzerland
Phone : [+[41] 22] 37 964 50, FAX : [+[41] 22] 37 961 08
mailto : [EMAIL PROTECTED]
URL : http://www.unige.ch/sciences/crystal/cerny/rcerny.htm
