[Ifeffit] Linear Combination Fitting using ATHENA

[Matthew Marcus]

I have a good spectrum for synthetic magnetite, but I gather that this is not what you want.  Magnetite is tricky because most natural
samples are impure and oxidized.
	mam

On 8/11/2013 9:36 PM, Teck Kwang Choo wrote:
> That's magnetite unfortunately!
>
>
> On 12 August 2013 14:02, Scott Calvin <scalvin at sarahlawrence.edu <mailto:scalvin at sarahlawrence.edu>> wrote:
>
>     Yes it does, Teck Kwang: http://millenia.cars.aps.anl.gov/cgi-bin/newville/Model-Search.cgi/ModelData/fe3o4_rt01_mar02.xmu
>
>     --Scott Calvin
>     Sarah Lawrence College
>
>     On Aug 11, 2013, at 11:12 PM, Teck Kwang Choo <teck.kwang.choo at monash.edu <mailto:teck.kwang.choo at monash.edu><mailto:teck.kwang.choo at monash.edu <mailto:teck.kwang.choo at monash.edu>>> wrote:
>
>     The database: http://cars.uchicago.edu/~newville/ModelLib/search.html<http://cars.uchicago.edu/%7Enewville/ModelLib/search.html> does not seem to have Ferrite.
>
>     The matrix of my sample is largely Mg-ferrite where Fe is in the form of Fe (III). If you anyone has the spectra for Mg-ferrite, would it be possible to provide it to me? Otherwise, I do not think my sample spectra would be useable at all!
>
>     Thanks and kind regards.
>
>
>     On 10 August 2013 02:21, Matthew Marcus <mamarcus at lbl.gov <mailto:mamarcus at lbl.gov><mailto:mamarcus at lbl.gov <mailto:mamarcus at lbl.gov>>> wrote:
>     I would guess that you need better standards.  In particular, FeO is not your typical Fe(II) mineral or oxide.  What is the system you're working on?
>     I have an extensive collection of Fe XANES reference spectra, including a number of Fe(II) species.
>
>     LCF gives you the fraction of Fe atoms included in the sample.  For example, suppose you had a sample which was genuinely a mix representable
>     as FeO.Fe2O3.  Then, LCF would properly report 2/3 Fe2O3 + 1/3 FeO because 2/3 of the Fe atoms are in the Fe2O3 fraction.
>              mam
>
>
>     On 8/8/2013 8:37 PM, Teck Kwang Choo wrote:
>     Hello,
>
>     I have been using ATHENA to perform Linear Combination Fitting (LCF) on my XANES spectrum to quantify the amounts of Fe (II) and Fe (III) in my samples using only FeO and Fe2O3 as standards. The results showed a majority of Fe (II), which is contrary to what was expected.
>
>     This made me wonder if the LCF results from XANES is a molar percentage (mol %) or weight percentage (wt%).
>
>     Could anyone enlighten me on this matter?
>
>     Thanks!
>
>     --
>     Teck Kwang Choo
>     PhD Student
>     Department of Chemical Engineering
>     Room 225, Building 36
>     Monash University
>     Mobile No.: 04-11489904
>
>
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>     --
>     Teck Kwang Choo
>     PhD Student
>     Department of Chemical Engineering
>     Room 225, Building 36
>     Monash University
>     Mobile No.: 04-11489904
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> --
> Teck Kwang Choo
> PhD Student
> Department of Chemical Engineering
> Room 225, Building 36
> Monash University
> Mobile No.: 04-11489904
>
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