[Ifeffit] MoS2 fit

Bruce Ravel ravel at phys.washington.edu
Thu Nov 11 16:11:31 CST 2004

On Thursday 11 November 2004 01:12 pm, Grant Bunker wrote:
> I haven't played with these data or this analysis, but the difficulty in
> fitting the known structure may suggest a problem with the data.
> One experimental problem that springs to mind, since MoS2 is a layered
> structure, is whether there might be a preferred orientation in the sample
> particles, i.e. the particles might not be randomly oriented. Since
> the x-ray beam is polarized this could cause some serious weirdness in the
> XAFS fitting (if the polarization weren't explicitly considered).

If preferred orientation is indeed the culprit, that could be determined by 
comparing a diffractogram of the sample used in the XAS experiment with the 
calculated peak ratios.


 Bruce Ravel  ----------------------------------- ravel at phys.washington.edu
 Code 6134, Building 3, Room 222
 Naval Research Laboratory                          phone: (1) 202 767 2268
 Washington DC 20375, USA                             fax: (1) 202 767 4642

 NRL Synchrotron Radiation Consortium (NRL-SRC)
 Beamlines X11a, X11b, X23b
 National Synchrotron Light Source
 Brookhaven National Laboratory, Upton, NY 11973

 My homepage:    http://feff.phys.washington.edu/~ravel 
 EXAFS software: http://feff.phys.washington.edu/~ravel/software/exafs/

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