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June 2012

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JEOL-Focused Probe Users List <[log in to unmask]>
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Wed, 20 Jun 2012 09:06:24 +0200
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*

Ritchie,

what an exciting prospect! I hope your case will be successful.

I work at an institute that's mainly focused on materials research. We
are using a medium-old SEM (W cathode) and a medium-new EPMA (JXA-8100).
Our researchers as well as our industrial partners appreciate both
methods for their respective strengths.

Would your department cooperate with the the School of Engineering, i.e.
would your new microprobe be available to them? If so, I think they
should be quite supportive!

According to the website of the Research Centre for Surface and
Materials Science (RCSMS), their SEM equipment is new and provides
high-performance electron imaging thanks to their Field Emission (FE)
sources. A microprobe could and should not compete with that. However,
even high-performance FE SEMs can not provide better spectral EDS
resolution than the WDS of a microprobe. For example, how do they
resolve the problem of line overlaps, such as Mo and S?
Especially in our research field of high temperature materials, we often
look at alloys containing Mo, and aggressive environments containing S,
and we want to be able to tell what happens on and below the metal
surface when those alloys are exposed to high temperatures in aggressive
environments. You could think of other examples too, and I'm sure the
RCSMS would love to have a WDS solution at hand!

Another strength of the EPMA clearly is element mapping. Even the
coolest FE SEM will produce rather sad looking maps (some examples
provided on the RCSMS website). I bet if you show a comparison of EDS /
WDS maps this will convince some people! Especially industrial
researchers love our colourful WDS maps.

Finally, when it comes to precise quantification of alloying elements in
special steels or Nickel-base alloys, we know we cannot rely on EDS.
Even just the word "standardless" should ring some alarm bells!
Of course it will be challenging to make this point without sounding too
critical about the work that's been done at the RCSMS so far ;-)

Good luck!
Gerald

------------------------
Dr. Gerald Schmidt
DECHEMA-Forschungsinstitut
High Temperature Materials
Theodor-Heuss-Allee 25
60486 Frankfurt am Main
Germany
 
Tel:     +49-69-7564-355
Fax:    +49-69-7564-388
E-Mail: [log in to unmask]
http://www.dechema-dfi.de
 
DECHEMA-Forschungsinstitut • Stiftung bürgerlichen Rechts
Vorstand: Prof. Dr.-Ing. Michael Schütze (Vors.), Priv.-Doz. Dr. Jens
Schrader
Sitz der Stiftung: Frankfurt am Main
Anerkannt durch das Regierungspräsidium Darmstadt unter Az.
I13-25d04/11-(12)-720
Steuer-Nr.: 45 255 00182


-----Ursprüngliche Nachricht-----
Von: JEOL-Focused Probe Users List [mailto:[log in to unmask]] Im
Auftrag von Ritchie Sims
Gesendet: Donnerstag, 14. Juni 2012 09:12
An: [log in to unmask]
Betreff: [PROBEUSERS] Case for a new EPMA


Hi

For the past ten years we have been using a JXA-840A with EDS for
quantitative geological 
work, it's been OK, for analytes > about 0.2%, but there is a chance now
to make a case for 
a brand-new 'proper' EPMA.

The complication is that we have to find as many potential users, from
within and without the 
University, to support us.

In the School of Engineering there are a couple of SemS, with close ties
to local industry, and 
because their standardless analytical packages give element
concentrations to two decimal 
places, they and their users accept that their results are quantitative
(!).

They are likely to oppose our getting a new EPMA as it would probably
reduce their revenue 
stream.

I know virtually nothing of probe applications outside Geology.

I would really appreciate hearing of EPMA projects and applications in
non-geological fields 
to help me prepare a case. It would be great to list those for which an
EPMA beats an SEM 
hands-down.

cheers

Ritchie

--
Ritchie Sims Ph D				Phone : 64 9 3737599 ext
87713
Microanalyst                 				Fax   : 64 9
3737435
Department of Geology        			email :
[log in to unmask]
The University of Auckland   
Private Bag 92019
Auckland
New Zealand

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