<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=Content-Type content="text/html; charset=iso-8859-1">
<META content="MSHTML 6.00.6000.21342" name=GENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=#ffffff>
<DIV><FONT face="Courier New" size=2>Yup. That's consistent. That
sort of thing is why every XANES paper should state clearly</FONT></DIV>
<DIV><FONT face="Courier New" size=2>the basis of the energy calibration.
With Newville's database, you can often figure that</FONT></DIV>
<DIV><FONT face="Courier New" size=2>out yourself because many of the spectra
were done with a reference foil.</FONT></DIV>
<DIV><FONT face="Courier New" size=2> mam</FONT></DIV>
<DIV>----- Original Message ----- </DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=teck.kwang.choo@monash.edu
href="mailto:teck.kwang.choo@monash.edu">Teck Kwang Choo</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=ifeffit@millenia.cars.aps.anl.gov
href="mailto:ifeffit@millenia.cars.aps.anl.gov">XAFS Analysis using
Ifeffit</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Wednesday, August 14, 2013 1:07
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [Ifeffit] Linear Combination
Fitting using ATHENA</DIV>
<DIV><BR></DIV>
<DIV dir=ltr>Yes Matthew, I used 7112 eV for my Fe K-edge calibration. I am
guessing that is the reason a ~+1 eV shift in your maghemite spectrum is
required is required to fit mine. Both pre-edge features match in the sense
that they are roughly bound by the same energy values.<BR></DIV>
<DIV class=gmail_extra><BR><BR>
<DIV class=gmail_quote>On 14 August 2013 17:30, Matthew Marcus <SPAN
dir=ltr><<A href="mailto:mamarcus@lbl.gov"
target=_blank>mamarcus@lbl.gov</A>></SPAN> wrote:<BR>
<BLOCKQUOTE class=gmail_quote
style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid"><U></U>
<DIV bgcolor="#ffffff">
<DIV><FONT face="Courier New">That depends on the way you did your
calibration. If it really matches, including the</FONT></DIV>
<DIV><FONT face="Courier New">pre-edge features, with a 1eV shift, then
that's what you probably have. Did you take</FONT></DIV>
<DIV><FONT face="Courier New">into account my calibration, which puts the Fe
K-edge at 7110.75eV? Some people use other</FONT></DIV>
<DIV><FONT face="Courier New">values like 7112eV.</FONT></DIV>
<DIV><FONT face="Courier New"> mam</FONT></DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV class=im>
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV style="BACKGROUND: #e4e4e4; FONT: 10pt arial"><B>From:</B> <A
title=teck.kwang.choo@monash.edu href="mailto:teck.kwang.choo@monash.edu"
target=_blank>Teck Kwang Choo</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=ifeffit@millenia.cars.aps.anl.gov
href="mailto:ifeffit@millenia.cars.aps.anl.gov" target=_blank>XAFS
Analysis using Ifeffit</A> </DIV></DIV>
<DIV class=im>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Tuesday, August 13, 2013 9:20
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [Ifeffit] Linear
Combination Fitting using ATHENA</DIV>
<DIV><BR></DIV></DIV>
<DIV>
<DIV class=h5>
<DIV dir=ltr>
<DIV>
<DIV>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<BR>I have found that there is a +1eV shift of my spectrum
relative to the maghemite one, probably due to slight differences in
beamline. Do you think it is alright to make a +1 eV shift to the
maghemite spectrum (or -1eV shift to my sample
spectrum)?<BR><BR></DIV>Thanks.<BR><BR></DIV>Kind regards.<BR><BR>Teck
Kwang<BR></DIV>
<DIV class=gmail_extra><BR><BR>
<DIV class=gmail_quote>On 14 August 2013 10:07, Teck Kwang Choo <SPAN
dir=ltr><<A href="mailto:teck.kwang.choo@monash.edu"
target=_blank>teck.kwang.choo@monash.edu</A>></SPAN> wrote:<BR>
<BLOCKQUOTE class=gmail_quote
style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">
<DIV dir=ltr>
<DIV>Thanks Matthew for the spectra.<BR><BR></DIV>
<DIV>Is it correct to use the spectra that was taken in transmission
mode (the one you did) to fit those taken in fluorescence mode (my
case)?<SPAN><FONT color=#888888><BR><BR></FONT></SPAN></DIV><SPAN><FONT
color=#888888>
<DIV>Teck Kwang<BR></DIV></FONT></SPAN></DIV>
<DIV>
<DIV>
<DIV class=gmail_extra><BR><BR>
<DIV class=gmail_quote>On 14 August 2013 01:37, Matthew Marcus <SPAN
dir=ltr><<A href="mailto:mamarcus@lbl.gov"
target=_blank>mamarcus@lbl.gov</A>></SPAN> wrote:<BR>
<BLOCKQUOTE class=gmail_quote
style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">Here
are reference spectra. The calibration is defined with the Fe
metal edge at 7110.75eV. The maghemite spectrum has been
corrected for mild<BR>overabsorption by reference to magnetite, which
is very similar. The magnetite is synthetic Fe3O4 from Aldrich,
and done in TEY, so no overabsorption.<BR>The maghemite is from
oxidation of Fe oxide nanoparticles and has been verified by XRD and
comparison with the ETH group's maghemite spectrum.<BR>
mam
<DIV><BR><BR>On 8/13/2013 1:33 AM, Teck Kwang Choo wrote:<BR></DIV>
<BLOCKQUOTE class=gmail_quote
style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">
<DIV>Hi all,<BR><BR>@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!<BR><BR>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.<BR><BR>@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!<BR><BR>Thanks for all your responses! It is
greatly appreciated! This forum has been more helpful than I
thought!<BR><BR>Teck Kwang<BR><BR><BR></DIV>
<DIV>On 13 August 2013 01:34, Matthew Marcus <<A
href="mailto:mamarcus@lbl.gov" target=_blank>mamarcus@lbl.gov</A>
<mailto:<A href="mailto:mamarcus@lbl.gov"
target=_blank>mamarcus@lbl.gov</A>>> wrote:<BR><BR>
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<BR> of any facility that can
do it on a micro scale. Is there one?<BR>
mam<BR><BR><BR> On 8/12/2013
7:01 AM, Alexandre dos Santos Anastacio wrote:<BR><BR>
Hello,<BR><BR> 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:<BR><BR></DIV>
10.1109/TMAG.2009.2018880 <<A
href="http://dx.doi.org/10.1109/__TMAG.2009.2018880"
target=_blank>http://dx.doi.org/10.1109/__<U></U>TMAG.2009.2018880</A>
<<A href="http://dx.doi.org/10.1109/TMAG.2009.2018880"
target=_blank>http://dx.doi.org/10.1109/<U></U>TMAG.2009.2018880</A>>><BR><BR>
Alexandre.
<DIV><BR><BR><BR><BR><BR>
______________________________<U></U>___________________<BR>
Ifeffit mailing list<BR>
Ifeffit@millenia.cars.aps.anl.<U></U>__gov <mailto:<A
href="mailto:Ifeffit@millenia.cars.aps.anl.gov"
target=_blank>Ifeffit@millenia.cars.<U></U>aps.anl.gov</A>><BR>
<A href="http://millenia.cars.aps.anl."
target=_blank>http://millenia.cars.aps.anl.</A>_<U></U>_gov/mailman/listinfo/ifeffit
<<A
href="http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit"
target=_blank>http://millenia.cars.aps.anl.<U></U>gov/mailman/listinfo/ifeffit</A>><BR><BR>
______________________________<U></U>___________________<BR>
Ifeffit mailing list<BR>
Ifeffit@millenia.cars.aps.anl.<U></U>__gov <mailto:<A
href="mailto:Ifeffit@millenia.cars.aps.anl.gov"
target=_blank>Ifeffit@millenia.cars.<U></U>aps.anl.gov</A>><BR></DIV>
<A href="http://millenia.cars.aps.anl."
target=_blank>http://millenia.cars.aps.anl.</A>_<U></U>_gov/mailman/listinfo/ifeffit
<<A
href="http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit"
target=_blank>http://millenia.cars.aps.anl.<U></U>gov/mailman/listinfo/ifeffit</A>>
<DIV><BR><BR><BR><BR><BR>--<BR>Teck Kwang Choo<BR>PhD
Student<BR>Department of Chemical Engineering<BR>Room 225, Building
36<BR>Monash University<BR>Mobile No.: 04-11489904<BR><BR><BR></DIV>
<DIV>______________________________<U></U>_________________<BR>Ifeffit
mailing list<BR><A href="mailto:Ifeffit@millenia.cars.aps.anl.gov"
target=_blank>Ifeffit@millenia.cars.aps.anl.<U></U>gov</A><BR><A
href="http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit"
target=_blank>http://millenia.cars.aps.anl.<U></U>gov/mailman/listinfo/ifeffit</A><BR><BR></DIV></BLOCKQUOTE><BR>_______________________________________________<BR>Ifeffit
mailing list<BR><A href="mailto:Ifeffit@millenia.cars.aps.anl.gov"
target=_blank>Ifeffit@millenia.cars.aps.anl.gov</A><BR><A
href="http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit"
target=_blank>http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit</A><BR><BR></BLOCKQUOTE></DIV><BR><BR
clear=all><BR>-- <BR><SPAN
style="FONT-FAMILY: arial,helvetica,sans-serif">Teck Kwang
Choo</SPAN><BR>PhD Student<BR>Department of Chemical Engineering<BR>Room
225, Building 36<BR>Monash University<BR>Mobile No.:
04-11489904<BR></DIV></DIV></DIV></BLOCKQUOTE></DIV><BR><BR
clear=all><BR>-- <BR><SPAN
style="FONT-FAMILY: arial,helvetica,sans-serif">Teck Kwang
Choo</SPAN><BR>PhD Student<BR>Department of Chemical Engineering<BR>Room
225, Building 36<BR>Monash University<BR>Mobile No.:
04-11489904<BR></DIV></DIV></DIV>
<P></P>
<HR>
<DIV class=im>
<P></P>_______________________________________________<BR>Ifeffit mailing
list<BR><A href="mailto:Ifeffit@millenia.cars.aps.anl.gov"
target=_blank>Ifeffit@millenia.cars.aps.anl.gov</A><BR><A
href="http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit"
target=_blank>http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit</A><BR></DIV>
<P></P></BLOCKQUOTE></DIV><BR>_______________________________________________<BR>Ifeffit
mailing list<BR><A
href="mailto:Ifeffit@millenia.cars.aps.anl.gov">Ifeffit@millenia.cars.aps.anl.gov</A><BR><A
href="http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit"
target=_blank>http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit</A><BR><BR></BLOCKQUOTE></DIV><BR><BR
clear=all><BR>-- <BR><SPAN
style="FONT-FAMILY: arial,helvetica,sans-serif">Teck Kwang Choo</SPAN><BR>PhD
Student<BR>Department of Chemical Engineering<BR>Room 225, Building
36<BR>Monash University<BR>Mobile No.: 04-11489904<BR></DIV>
<P>
<HR>
<P></P>_______________________________________________<BR>Ifeffit mailing
list<BR>Ifeffit@millenia.cars.aps.anl.gov<BR>http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit<BR></BLOCKQUOTE></BODY></HTML>