Re: [Ifeffit] Ifeffit Digest, Vol 129, Issue 9

Just curious, how challenging was such fitting analysis. In the both models, the first nearest neighbors are Mo-O and their EXAFS contributions should be virtually the same, whether you use Li2MoO3 or MoO3 structures. Hence, to use EXAFS fitting for determining their mixing fraction in your unknown sample you should probably analyze the data beyond the first shell which is likely to be very challenging in such heterogeneous case. Alternatively, because the oxidation states of Mo in these standards are evidently different, there should be a strong XANES contrast between them, the energy shifts and such. Wouldn't it be easier to use a linear combination fit to find your mixing fraction from XANES analysis? Anatoly ________________________________________ From: ifeffit-bounces@millenia.cars.aps.anl.gov [ifeffit-bounces@millenia.cars.aps.anl.gov] on behalf of KONG Qingyu [qingyu.kong@synchrotron-soleil.fr] Sent: Friday, November 08, 2013 4:04 AM To: ifeffit@millenia.cars.aps.anl.gov Subject: Re: [Ifeffit] Ifeffit Digest, Vol 129, Issue 9 Hello Jason, Thank you. Could one obtain x% directly from Artemis? We have tried to use a separate program to do linear combination fitting using feff calculated paths, but not the same quality of fitting from Artemis. Best regards, Qingyu Kong -----Message d'origine----- De : ifeffit-bounces@millenia.cars.aps.anl.gov [mailto:ifeffit-bounces@millenia.cars.aps.anl.gov] De la part de ifeffit-request@millenia.cars.aps.anl.gov Envoyé : jeudi 7 novembre 2013 19:00 À : ifeffit@millenia.cars.aps.anl.gov Objet : Ifeffit Digest, Vol 129, Issue 9 Send Ifeffit mailing list submissions to ifeffit@millenia.cars.aps.anl.gov To subscribe or unsubscribe via the World Wide Web, visit http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit or, via email, send a message with subject or body 'help' to ifeffit-request@millenia.cars.aps.anl.gov You can reach the person managing the list at ifeffit-owner@millenia.cars.aps.anl.gov When replying, please edit your Subject line so it is more specific than "Re: Contents of Ifeffit digest..." Today's Topics: 1. linear combination fitting (KONG Qingyu) 2. Re: linear combination fitting (Jason Gaudet) ---------------------------------------------------------------------- Message: 1 Date: Wed, 6 Nov 2013 19:57:07 +0000 From: KONG Qingyu To: "ifeffit@millenia.cars.aps.anl.gov" Subject: [Ifeffit] linear combination fitting Message-ID: <30F62EE734A9EA45A3F211513CB62003B134D787@SUN-DAG1.synchrotron-soleil.fr> Content-Type: text/plain; charset="iso-8859-1" Hello, We measured EXAFS of a mixed sample of Li2MoO3 and MO3, with Artemis we fitted the data with two FEFF calculations using the crystal structures of Li2MoO3 and MO3, the fitting results are quite good. We would like to know the weight of Li2MoO3 and MO3 in the sample, how can we get this value from Artemis? Thanks a lot in advance. Qingyu Kong Beamline ODE Soci?t? civile Synchrotron SOLEIL L'Orme des Merisiers Saint-Aubin - BP 48 91192 GIF-sur-YVETTE CEDEX Tel: +33 (0)1 69 35 97 84 (office) +33 (0)1 69 35 97 16 (beamline) email: kong@synchrotron-soleil.fr ------------------------------ Message: 2 Date: Wed, 6 Nov 2013 18:03:53 -0500 From: Jason Gaudet To: XAFS Analysis using Ifeffit Subject: Re: [Ifeffit] linear combination fitting Message-ID: Content-Type: text/plain; charset="iso-8859-1" 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% using the formula weight of your components. -Jason On Wed, Nov 6, 2013 at 2:57 PM, KONG Qingyu < qingyu.kong@synchrotron-soleil.fr> wrote:

Hello,

We measured EXAFS of a mixed sample of Li2MoO3 and MO3, with Artemis we fitted the data with two FEFF calculations using the crystal structures of Li2MoO3 and MO3, the fitting results are quite good. We would like to know the weight of Li2MoO3 and MO3 in the sample, how can we get this value from Artemis?

Thanks a lot in advance.

Qingyu Kong