Dear Lee,
Your calculations are correct provided the allowances for microabsorption and
other effects were made properly.
Regards,
Leonid
--- On Tue, 10/14/08, Lee Gerrard <[EMAIL PROTECTED]> wrote:
> From: Lee Gerrard <[EMAIL PROTECTED]>
> Subject: Question on QPA - Amorphous/crystalline mix
> To: rietveld_l@ill.fr
> Date: Tuesday, October 14, 2008, 1:20 PM
> I have a question for the list as I know there are a number
> of people
> working on QPA. Ok the question is as follows:-
>
> We have a mixture of a number of crystalline phases (A and
> B) and an
> amorphous (glassy) phase. We can do Rietveld refinement on
> this and get
> weight percentage (wt.%) values for the crystalline
> components. We have
> added a known amount of corundum as a standard and refined
> again.
> Example values we get are as follows:-
>
> Phase A 10 wt.%
> Phase B 50 wt.%
> Corundum 40 wt.%
>
> BUT we know we have added only 33 wt.% corundum - are we
> able to
> calculate the wt.% of the amorphous content from the known
> values? I
> have tried scaling/ratio'ing the values to the known
> corundum amount
> therefore giving:-
>
> Phase A 8.25 %
> Phase B 41.25 %
> Corundum 33 %
>
> TOTAL 82.5 %
>
> which leaves 17.5 % left over. Hence must be the amorphous
> part??
>
> I am not totally convinced by this method at all and would
> love to know
> how is best to go about solving this problem.
>
> Many thanks,
>
> Lee
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Dr. Lee A. Gerrard BSc CChem CSci MRSC
> Materials Scientist
>
> Materials Science Research Division
> SB40.1
> AWE Plc
> Aldermaston, Reading,
> Berkshire
> RG7 4PR
>
> Tel: +44 (0)118 982 6516
> Fax: +44 (0)118 982 4739
> Email: [EMAIL PROTECTED]
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~
