Hello,
I'm using Demeter 0.9.21 on Windows 7 (32 bit).
I encountering a few problems with Athena. So I wonder if it can be solved
in future releases.
1. The names of my spectra are quite long (around 40 characters). The first
problem is when I try to import data from Athena project file:
Hi Qingyu,
Each Mo absorber contributes to the spectrum equally, so if you think you
have a good analysis that indicates x% of Mo scatterers are most similar to
Li2MoO3 and 100-x% are most similar to MoO3, those are simply atomic
percentages. All you have to do is convert the atomic% to mass%
] Linear Combination Fitting using ATHENA
Also Matthew, I have found that my sample spectrum is an almost exact
replica of the maghemite spectrum, the only differences being the
absorbance height of the edge-peak (highest peak), which is ok but more
importantly
I have found that there is a +1eV
use other
values like 7112eV.
mam
- Original Message -
*From:* Teck Kwang Choo teck.kwang.c...@monash.edu
*To:* XAFS Analysis using Ifeffit ifeffit@millenia.cars.aps.anl.gov
*Sent:* Tuesday, August 13, 2013 9:20 PM
*Subject:* Re: [Ifeffit] Linear Combination Fitting using ATHENA
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
Here are reference spectra. The calibration is defined with the Fe metal edge
at 7110.75eV. The maghemite spectrum has been corrected for mild
overabsorption by reference to magnetite, which is very similar. The magnetite
is synthetic Fe3O4 from Aldrich, and done in TEY, so no
Hi all!
I am out of my place and I can not check it now, but I believe that in the
database of XAFS (or something like that) there are some spectra of
maghemites obtained by Lytle long time ago.
Best regards
Maria Elena Montero Cabrera
El ago 13, 2013 3:38 a.m., Teck Kwang Choo
Also Matthew, I have found that my sample spectrum is an almost exact
replica of the maghemite spectrum, the only differences being the
absorbance height of the edge-peak (highest peak), which is ok but more
importantly
I have found that there is a +1eV shift of my spectrum relative to the
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
Alexandre.
---
From: ifeffit-boun...@millenia.cars.aps.anl.gov
[mailto:ifeffit-boun...@millenia.cars.aps.anl.gov] On Behalf Of Alexandre dos
Santos Anastacio
Sent: Monday, August 12, 2013 9:01 AM
To: XAFS Analysis using Ifeffit
Subject: Re: [Ifeffit] Linear Combination Fitting using ATHENA
Hello
The database: http://cars.uchicago.edu/~newville/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
That's magnetite unfortunately!
On 12 August 2013 14:02, Scott Calvin scal...@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
Dear Teck Kwang Choo,
it is the ratio of the number of (in your case) iron atoms. This ratio
has no unit. You will therefore get the same number if you calculate
molar % ratio or weight % (Except you consider the weight of the missing
electron in Fe3+... :-). Now, if you weigh your standards and
Thanks for your reply Edmund.
I agree with you that I might have not chosen the right standards for my
sample. In fact, XRD analysis have confirmed that Ferrite is the main form
of Fe in my sample but I did not have any ferrite standards during XANES
analysis. Was wondering if you happen to have
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
Dear Bruce,
I am using Dathena to do some linear combination fitting. In your program, you
give three methods for fitting, nomal, derivate and chi(k). I got three
different results using these methods. My question is which one is better to
obtain more reasonable result or what the purpose of
Hi there,
Is there a way to do Linear combination fitting in Athena with data
which were already proceeded (background corrected and normalized)? I
don't want to do a double background correction /normalization on these
data. However the Linear Combination Fitting dialog gives only the
option
On Wednesday 02 September 2009 01:24:51 pm Jens Kruse wrote:
Thanks for the fast answers. Attached is a screenshot. Maybe I just read
the pages incorrectly.
Auugghhh!!! You're right! I load up the table on the conbinatorics
page with chisqr rather than chinu. I have looked at that literally
dear all,
thanks for your help.
guven
- Original Message -
From: Dominik Samuelis d.samue...@fkf.mpg.de
Date: Tuesday, April 7, 2009 3:18 pm
Subject: Re: [Ifeffit] Linear combination fitting
To: XAFS Analysis using Ifeffit ifeffit@millenia.cars.aps.anl.gov
Dear Guvenc,
Shelly
://ag.udel.edu/soilchem/zhu.html
Original message
Date: Wed, 08 Apr 2009 23:20:32 +0200
From: ifeffit-boun...@millenia.cars.aps.anl.gov (on behalf of Dominik Samuelis
d.samue...@fkf.mpg.de)
Subject: Re: [Ifeffit] Linear combination fitting
To: XAFS Analysis using Ifeffit ifeffit
-Original Message-
From: ifeffit-boun...@millenia.cars.aps.anl.gov [mailto:ifeffit-
boun...@millenia.cars.aps.anl.gov] On Behalf Of Guvenc Akgul
Sent: Monday, April 06, 2009 4:31 PM
To: ifeffit@millenia.cars.aps.anl.gov
Subject: [Ifeffit] Linear combination fitting
Dear all,
I have done Ti
Hi Guven,
This is not unusual, in my experience, particularly if the chi(k) fit
is not particularly good.
XANES and EXAFS are sensitive to different aspects of the local
environment. In particular, the chi(k) is much more affected by
structure beyond the nearest-neighbors. In your system,
Dear Guvenc,
Shelly and Scott have already replied to this issue, and I fully agree
with their points. Nevertheless, I'd like to add some points, that
generally apply to linear component fits.
The huge discrepancy between chi(k) and norm(E) fit very likely is an
indication that your data
Hi everyone,
I just learned that before Athena there was no such program to check on
all combinations, so it was not that confusing - or just more work?
I think this feature of Athena is very good tool, but when I really do
not know what is in my sample how can it help?
I try to answer it
On Thursday 17 July 2008 08:53:00 Gudrun Lisa Bovenkamp wrote:
Hi everyone,
I just learned that before Athena there was no such program to check on
all combinations, so it was not that confusing - or just more work?
I think this feature of Athena is very good tool, but when I really do
not
Hi,
I have a general basic question about linear combination fitting (LCF)
with Athena.
I have XANES spectra from two different mixtures. Both were mixed from
two reference compounds in a 1:3 ratio. In one mixture the ratio is
based on the weight of both reference compounds and in the other
On Tuesday 06 November 2007 11:33:16 Jens Kruse wrote:
Hi,
I have a general basic question about linear combination fitting (LCF)
with Athena.
I have XANES spectra from two different mixtures. Both were mixed from
two reference compounds in a 1:3 ratio. In one mixture the ratio is
based on
I'm trying to do linear combination fitting on a number of samples, and
its working well for the most part, with 4 exceptions. There are 4
samples, of 22, that I can't get to sum to 1, despite the fact that I have
sum to 1 checked off before fitting. I've tried reprocessing the data,
and tried
Subject: [Ifeffit] Linear Combination Fitting in Athena
I'm trying to do linear combination fitting on a number of samples, and
its working well for the most part, with 4 exceptions. There are 4
samples, of 22, that I can't get to sum to 1, despite the fact that I
have
sum to 1 checked off before
A couple questions about linear combination fitting in Athena:
1. There is the option of floating an E0 for the standards, is there any
way to restrict how much it floats, ie. constrain it to +/-0.4eV shifts
during fitting?
2. If I am fitting normalized u(E), and only care about the XANES region
Hi Skya,
On Thursday 06 September 2007, Skya Fawcett wrote:
A couple questions about linear combination fitting in Athena:
1. There is the option of floating an E0 for the standards, is there any
way to restrict how much it floats, ie. constrain it to +/-0.4eV shifts
during fitting?
The
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