Patrick Weisbecker wrote:
> Hello,
>
> About influence of misalignement on peak assymetry; A good mean to
improve
> symetry of peaks at low angles is to use soller slits, indeed other
> parameters than alignement can be responsible for asymetry.
>
> As for modeling peak shape, I use Fullprof and i also have
difficulties to
> find a good agreement between experimental and calculated pattern
because
> of asymetry at low angles.
> If someone knows if a particular profile (on this sofware) is best
suited
> for asymetry i will appreciate.
I find FULLPROF works OK if I split the pattern up into 2 segments.
Below 20
two theta (using CuKalpha) and greater than 20 two theta and fit
asymmetry
seperatly for the two sets of data. The asymmetry parameters dont seem
to be
very effective if one attempts to match the entire pattern
simultaneously.
>
>
> Patrick
--
****************************************************************************
Bruce A. Weir,
Optoelectronics,
Cavendish Laboratory,
University Of Cambridge,
Madingley Rd,
Cambridge,
CB3 0HE
U.K.
Tel: +44 01223 337285
http://www.geocities.com/timessquare/bunker/6614
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"She had a pretty gift for quotation,
which is a serviceable substitute for wit."
- - - W. Somerset Maugham
