[meteorite-list] Meteorite Classification Question - Instruments

From: Mark Grossman <markig_at_meteoritecentral.com>
Date: Sat, 14 Jan 2012 12:54:27 -0500
Message-ID: <645B41DC4665450DAC60791B6C26E1EF_at_QED>

I may have missed part of the discussion, but isn't XPS the acronym for
X-ray photoelectron spectroscopy? I haven't followed the development of the
instrument for many years, but it used to be used for surface spectroscopy.
It would only sample the first atomic layer or so of the substrate that was
being analyzed, and its major advantage was that it would not only tell you
what some of the elements were on the surface, it would provide the valence
or oxidation state of the element. This information would tell you
something about how the element was combined with other elements on the
surface. Perhaps the valence information might be helpful in identifying
mineral species. I believe that SEM and TEM will not provide valence
information. And yes, I believe the XPS has been provided with mapping
capability since I used to follow the subject.

If anybody can fill me in on whether this is the XPS that is being talked
about, and if there have been any meteorite studies using XPS, it would be
much appreciated.

Mark Grossman
Meteorite Manuscripts


----- Original Message -----
From: "Carl Agee" <agee at unm.edu>
To: "meteoritelist meteoritelist" <meteorite-list at meteoritecentral.com>
Sent: Saturday, January 14, 2012 12:30 PM
Subject: [meteorite-list] Meteorite Classification Question - Instruments


> Hi Robert,
>
> The electron microprobe is the instrument of choice for quantitative
> analyses of major elements of silicate minerals like olivine. SEM is
> great for qualitative analyses, quickly to see what elements are
> present - energy dispersive spectroscopy is nice technique to screen
> iron meteorites unknowns for example. As I understand it the XPS is
> used primarily imaging like an SEM, also chemical mapping. The ion
> beam instrument is a fabulous state-of-the-art device for imaging at
> very high resolution and can be used for micro- nano-milling and
> manipulation. These last two are amazing research tools, but not
> really what you need, right off the bat, for basic classification
> work.
>
> You must be at a very high-powered research facility!
>
> Carl Agee
>
> ----------------------------------------------------------
> Message: 2
> Date: Fri, 13 Jan 2012 13:10:54 -0800 (PST)
> From: Robert Beauford <robertbeauford at rocketmail.com>
> Subject: [meteorite-list] Meteorite Classification Question -
> Instruments
> To: "meteorite-list at meteoritecentral.com"
> <meteorite-list at meteoritecentral.com>
> Message-ID:
> <1326489054.80741.YahooMailNeo at web111002.mail.gq1.yahoo.com>
> Content-Type: text/plain; charset=iso-8859-1
>
> As I recall, there are several people on the list that actively
> classify meteorites, so I'm hoping one of you will be patient with a
> question that may be profoundly ignorant.
> I have access, in house, to a?FEI Nova Nanolab 200 Dual-Beam Focused
> Ion Beam or a?PHI VersaProbe XPS instrument, (along with SEM and TEM)
> but not to a working electron microprobe or, ironically, the equipment
> to make thin sections.? I am not very familiar with the XPS or ion
> beam instrument.? Can I get the necessary olivine composition ratio to
> achieve classification of a chondrite with the XPS probe or the ion
> beam?or do I need to go somewhere?and use a proper electron
> microprobe?? I would be truly grateful if any of you would take the
> time to advise.
> Thanks so much,
> -Robert??
>
>
> --
> Carl B. Agee
> Director and Curator, Institute of Meteoritics
> Professor, Earth and Planetary Sciences
> MSC03 2050
> University of New Mexico
> Albuquerque NM 87131-1126
>
> Tel: (505) 750-7172
> Fax: (505) 277-3577
> Email: agee at unm.edu
> http://meteorite.unm.edu/people/carl_agee/
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Received on Sat 14 Jan 2012 12:54:27 PM PST