Doug,
We used commercially available alpha-Al2O3 (corundum) for the recent IUCr-CPD round
robin on quantitative phase analysis. The source details are :-
Bailalox alumina polishing powder
Baikowski International Corporation
Standard C 1.0 micron (scratch size - actual particle size approx 28micron)
It is available in commercial quantities and from memory was not very expensive.
Independent checks suggest it was better than 99% crystalline.
For further details see the first round robin paper - Madsen et al. J.Appl Cryst
(2001) 34, 409-426.
Cheers
o----------------------oo0oo---------------------------o
Ian Madsen
Science Adviser - Analytical Science
CSIRO Minerals
Box 312
Clayton South 3169
Victoria
AUSTRALIA
Phone +61 3 9545 8785 direct
+61 3 9545 8500 switch
0417 554 935 mobile
FAX +61 3 9562 8919
Email [EMAIL PROTECTED]
o----------------------oo0oo---------------------------o
-----Original Message-----
From: Allen, Douglas [mailto:[EMAIL PROTECTED]
Sent: Friday, 7 May 2004 1:14 PM
To: '[EMAIL PROTECTED]'
Speaking of internal standards. Can someone recommend a source of bulk
alumina to use for production samples. I don't find 'linde A' listed in the
Buehler catalog anymore. I'm not sure which of the various grades they list
to order or if there is a better place to order it.
Doug Allen
Usually just lurking on this list
-----Original Message-----
From: Jim Cline [mailto:[EMAIL PROTECTED]
Sent: Thursday, May 06, 2004 1:18 PM
To: [EMAIL PROTECTED]
Hi,
At 03:48 PM 5/6/2004 -0400, you wrote:
>Jim
>
>Excellent news! This amorphous standard issue has been driving me
>nuts. When you say phase purity do you mean purity in terms of
>crystalline phase content?
Yes.
Jim
>Pam
>
>Dr Pamela Whitfield CChem MRSC
>Energy Materials Group
>Institute for Chemical Process and Environmental Technology Building
>M12 National Research Council Canada
>1200 Montreal Road
>Ottawa ON K1A 0R6
>CANADA
>Tel: (613) 998 8462 Fax: (613) 991 2384
>Email: <mailto:[EMAIL PROTECTED]>
>ICPET WWW: http://icpet-itpce.nrc-cnrc.gc.ca
>
>
>-----Original Message-----
>From: Jim Cline [mailto:[EMAIL PROTECTED]
>Sent: May 6, 2004 3:43 PM
>To: [EMAIL PROTECTED]
>
>
>Hi all,
>
>This is to say that I'm am nearly finished with the re-certification of
>SRM 676 for amorphous content. The revised certificate, offering a
>discussion as to the certification method, will be on the NIST website
>shortly, after the review process is completed. The certified phase
>purity of SRM 676 (retroactive to units in the field) is 91.75% +/-
>1.5%.
>
>Regards,
>
>Jim
>
>At 01:44 PM 5/6/2004 -0400, you wrote:
> >Robert
> >
> >As previously mentioned many Rietveld programs will do what you want
> >if you're willing to do the amorphous content calculations by hand
> >afterwards. Some commercial software has it built in. I've done work
> >in this area, and there are some pitfalls of which you must be aware,
> >or your results may be VERY unreliable.
> >
> >1. microabsorption. If your phases are similar in composition and
> >your 'spike' phase has a similar absorption then this might not be a
> >problem. However, there are instances in which extreme
> >microabsorption can make a accurate determination practically
> >impossible (other than possibly changing your tube to a more friendly
> >wavelength). There is the Brindley correction that can sort of
> >correct moderate microabsorption, but you need to know
>your
> >particle size, and ideally it needs to have a narrow distribution.
>Reducing
> >the particle size of your sample to sub-micron levels helps
> >significantly.
> >
> >2. spike phase. Many so-called crystalline phases aren't as fully
> >crystalline as you might think. The SRM676 alumina had it's
> >amorphous content measured a while back using neutrons and came out
> >as 1.77 +- 0.68%. It doesn't sound alot but can make a big difference
> >to your final results. Many 'crystalline' phases can be significantly
> >higher. Microabsorption can be an issue with the spike so choose
> >your spike carefully, and ideally standardise it using SRM676.
> >Remember to include the error in the SRM676 amorphous content if
> >quoting absolute amorphous contents rather than relative amounts.
> >
> >3. particle statistics. This is equally as important when looking at
>purely
> >crystalline materials, but errors due to poor particle statistics can
>really
> >mess up amorphous content work. Ideally, micronise your sample
> >before running it, but if they're nanomaterials then it might not be
> >an issue.
> >
> >4. surface roughness. I noticed that you probably work with
>nanomaterials.
> >They tend to be fluffy, and such samples (at least on our instrument)
> >show noticeable surface roughness effects on low angle reflections.
> >If this is the case for your samples then you will either have to
> >correct it or
>densify
> >your sample somehow (or both).
> >
> >
> >Some of this stuff was covered in the results of the quantitative
> >analysis round robin a while back:
> >
> >Outcomes of the International Union of Crystallography Commission on
> >Powder Diffraction Round Robin on Quantitative Phase Analysis:
> >samples 1a to 1h I. C. Madsen, N. V. Y. Scarlett, L. M. D. Cranswick
> >and T. Lwin, J. Appl. Cryst. (2001). 34, 409-426
> >
> >Outcomes of the International Union of Crystallography Commission on
> >Powder Diffraction Round Robin on Quantitative Phase Analysis:
> >samples 2, 3, 4, synthetic bauxite, natural granodiorite and
> >pharmaceuticals N. V. Y. Scarlett, I. C. Madsen, L. M. D. Cranswick,
> >T. Lwin, E. Groleau,
>G.
> >Stephenson, M. Aylmore and N. Agron-Olshina
> >J. Appl. Cryst. (2002). 35, 383-400
> >
> >
> >It would be useful to cross-check your technique on a couple of dummy
> >samples if at all possible to make sure you're not being mislead.
> >Have fun!!
> >
> >Pam
> >
> >
> >
> >Dr Pamela Whitfield CChem MRSC
> >Energy Materials Group
> >Institute for Chemical Process and Environmental Technology Building
> >M12 National Research Council Canada
> >1200 Montreal Road
> >Ottawa ON K1A 0R6
> >CANADA
> >Tel: (613) 998 8462 Fax: (613) 991 2384
> >Email: <mailto:[EMAIL PROTECTED]>
> >ICPET WWW: http://icpet-itpce.nrc-cnrc.gc.ca
> >
> >
> >-----Original Message-----
> >From: Robert Mauricot [mailto:[EMAIL PROTECTED]
> >Sent: May 6, 2004 10:57 AM
> >To: [EMAIL PROTECTED]
> >
> >
> >Dear all,
> >
> >I have a powder diffraction of an amorphous multiphase material. I
> >want to do a quantitative analysis of the amorphous phase. Can
> >anyone tell me what software does it.
> >
> >Sincery
> >
> >R.mauricot
> >
> >
> >Cemes-CNRS
> >Toulouse 31077 France
> >Laboratoire NaNomat
>
>James P. Cline [EMAIL PROTECTED]
>Ceramics Division Voice (301) 975
>5793
>National Institute of Standards and Technology FAX (301) 975 5334 100
>Bureau Dr. stop 8520
>Gaithersburg, MD 20899-8523 USA
James P. Cline [EMAIL PROTECTED]
Ceramics Division Voice (301) 975
5793
National Institute of Standards and Technology FAX (301) 975 5334 100
Bureau Dr. stop 8520
Gaithersburg, MD 20899-8523 USA
