Re: [sdpd] LaB6 standard sample preparation

[Armel Le Bail <alb...@cristal.org>]

After annealing, a NIST standard ceases to be a standard, IMHO.

Moreover, annealing would increase the grain size, possibly, and would
lead to more risk of preferred orientation.

If you want to measure instrumental profile shape and FWHM (etc),
then  preferred orientation is not a real problem. You may characterize
your pattern by a Rietveld program in "structure factor extraction"
mode (i.e. without structure constraint), or by the Pawley method.
Who cares about the LaB6 crystal structure anyway ?

Think also to reference samples from Gem Dugout :
http://www.thegemdugout.com/
much less expensive than the NIST standards. Maybe
"reference samples" can be annealed, they are not really
"standards" after all, but they can be used if you do not
need an accuracy with 8 digits, if not more, on the cell parameters ;-).

Armel
http://www.cristal.org/course/



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