[Ifeffit] Linear Combination Fitting using ATHENA

Teck Kwang Choo teck.kwang.choo at monash.edu
Tue Aug 13 03:33:20 CDT 2013


Hi all,

@Drew Latta: I was wondering why the end members should be magnetite and
maghemite. Is it because they are both of inverse-spinel structure, the
difference only being that the latter has all Fe completely oxidized into
Fe(III)? Would you be able to provide the standard spectra to me if that is
the case? Thanks very much!

Previously I have only thought of using hematite (alpha-Fe2O3) and FeO as
end-members, both representing Fe(III) and Fe(II) respectively without
giving much thought to the structure Fe takes. I also had my doubts using
magnetite (Fe3O4) as a standard as it is a mixture of both Fe (II) and Fe
(III). But thanks to the insights Drew has given, I now think I should take
the Fe-coordination environment into account with the use of magnetite and
maghemite as standards.

@Alexandre and Matthew: I have obtained Mossbauer spectra of some of my
samples but like Drew said, it is not straightforward at this point in
time. Will see what I can do with the data I have!

Thanks for all your responses! It is greatly appreciated! This forum has
been more helpful than I thought!

Teck Kwang


On 13 August 2013 01:34, Matthew Marcus <mamarcus at lbl.gov> wrote:

> While it's true that Mossbauer is the gold standard for Fe valence
> determination, access to the technique isn't all that common, and I don't
> know
> of any facility that can do it on a micro scale.  Is there one?
>         mam
>
>
> On 8/12/2013 7:01 AM, Alexandre dos Santos Anastacio wrote:
>
>> Hello,
>>
>> maybe that fingerprinting technique would be Mossbauer spectroscopy. The
>> Fe(II)/Fe(III) ratio comes easily and also there are lots of papers about
>> Mg-ferrite, an example:
>>
>> 10.1109/TMAG.2009.2018880 <http://dx.doi.org/10.1109/**TMAG.2009.2018880<http://dx.doi.org/10.1109/TMAG.2009.2018880>
>> >
>>
>> Alexandre.
>>
>>
>>
>>
>> ______________________________**_________________
>> Ifeffit mailing list
>> Ifeffit at millenia.cars.aps.anl.**gov <Ifeffit at millenia.cars.aps.anl.gov>
>> http://millenia.cars.aps.anl.**gov/mailman/listinfo/ifeffit<http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit>
>>
>>  ______________________________**_________________
> Ifeffit mailing list
> Ifeffit at millenia.cars.aps.anl.**gov <Ifeffit at millenia.cars.aps.anl.gov>
> http://millenia.cars.aps.anl.**gov/mailman/listinfo/ifeffit<http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit>
>



-- 
Teck Kwang Choo
PhD Student
Department of Chemical Engineering
Room 225, Building 36
Monash University
Mobile No.: 04-11489904
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://millenia.cars.aps.anl.gov/pipermail/ifeffit/attachments/20130813/7ef40d3d/attachment.html>


More information about the Ifeffit mailing list