[sdpd] Re: Indexing by HRTEM

["Bruce A. Weir" <baw27... @cam.ac.uk>]

MartinUlrich_Schmidt... @de.clariant.com wrote:

> Indexing by electon microscopy: A personal remark
>
> We once had a powder diagram, which could be indexed only with
> the help of electron microscopy:
> It was an organic specimen, giving a medium-quality powder diagram.
> 27 of the 30 lines could be indexed  by a=16.24, c=9.23, beta = 99 degree.
> The values for b, alpha and gamma remained ambiguous.
> By HR-TEM we found not only the missing lattice parameters
> (b = 4.8, alpha=gamma=0), but we also detected, that c had to be doubled,
> i.e. the lines in the powder diagram corresponded to h0l with l=2n.
> Since that time, I prefer to make EM, if indexing is impossible or
> ambiguous.

That sounds pretty useful for a problem which I have at the moment, do you
know a good reference which discusses the procedure?



--
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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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