Re: [sdpd] LaB6 standard sample preparation

[Lachlan Cranswick <L.M.D.Cranswick...@dl.ac.uk>]

>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 ?

Refining the structure of LaB6 can be a useful check on the total
alignment of the XRD (e.g., getting good intensities as well).

Looking at the thermals of the Boron to check if they are reasonable
can be useful.  On a standard well aligned Philips 1710 / 1050
style system (of which quite good structure solution quality
data can be obtained if you are in the mood) - (the old NIST) 
LaB6 normally gave a physically reasonable structure refinement.

Lachlan.

-----------------------
Lachlan M. D. Cranswick
Collaborative Computational Project No 14 (CCP14)
    for Single Crystal and Powder Diffraction
  Birkbeck University of London and Daresbury Laboratory 
Postal Address: CCP14 - School of Crystallography,
                Birkbeck College,
                Malet Street, Bloomsbury,
                WC1E 7HX, London,  UK
Tel: (+44) 020 7631 6849   Fax: (+44) 020 7631 6803
E-mail: l.m.d.cranswick...@dl.ac.uk
WWW: http://www.ccp14.ac.uk


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