I had started with LSQ but switched to peak fitting because I was worried about the Ce(IV) reference. I have data for bulk CeO2 and Ce(OH)4, but doesn't this have some Ce(III) impurity in it? I'm not quite sure how to account for this when I do LSQ.
Another challenge I've had is in using the Ce(IV) refs for our nanoparticles, which are about 2-5 nm in diameter. Is there a good Ce(IV) ref for nanos that are in this size range? On Wed, Dec 7, 2016 at 2:37 PM, Matthew Marcus <mamar...@lbl.gov> wrote: > Instead of doing a bunch of peak fitting, try LSQ. Use CeO2 (bulk or > nanos) for one reference and some Ce(III) for the other. Consistency > check: see that the Ce(III) fraction is consistent over some set of Ce(III) > references. > Ce(III) has an assymetric white line, so it doesn't really fit a single > gaussian. CeO2, unlike other Ce(IV), has a shoulder on the first peak, and > the first peak is shifted left a little with respect to other Ce(IV). > mam > > > On 12/7/2016 10:33 AM, Stephanie Laga wrote: > >> Dear all, >> >> I am trying to extract the % Ce(III) from some CeO2 nanoparticle XAS >> data. I have been using moved the peak fitting function in Athena to model >> the XANES with an arctan background function and a series of gaussians. >> >> Looking through the literature I haven't seen too many specifics to using >> this approach (rationale for choosing the widths of peaks or how to define >> the background function). Similarly, doesn't seem to be much rationale for >> choosing a 4 vs 5 peak fit for the XANES. >> >> My main question is then...1) Is there a rational for picking the >> background function, specifically the height and width (can I let the >> height vary or should I be keeping a constant arctan through all samples)? >> >> Any advice is greatly appreciated! >> >> Stephanie >> >> >> _______________________________________________ >> Ifeffit mailing list >> Ifeffit@millenia.cars.aps.anl.gov >> https://urldefense.proofpoint.com/v2/url?u=http-3A__millenia >> .cars.aps.anl.gov_mailman_listinfo_ifeffit&d=CwICAg&c=-d >> g2m7zWuuDZ0MUcV7Sdqw&r=UZ6LahCCy9yRGAvO8QDSWFzQq7a3vkDZfWzr2 >> SslhiE&m=0g-Qe_mvavdjZMlwuLL_XAVOn-Hdw7MVoGFBObqHUUA&s= >> y4QQn_F6Rx9uwWVg4Z7oYxHOx_7ddARSk12pRgTuM3o&e= Unsubscribe: >> https://urldefense.proofpoint.com/v2/url?u=http-3A__millenia >> .cars.aps.anl.gov_mailman_options_ifeffit&d=CwICAg&c=-dg >> 2m7zWuuDZ0MUcV7Sdqw&r=UZ6LahCCy9yRGAvO8QDSWFzQq7a3vkDZfWzr2S >> slhiE&m=0g-Qe_mvavdjZMlwuLL_XAVOn-Hdw7MVoGFBObqHUUA&s=6Tqa >> DHnrgY2yWI_fJuteI2BzDNW0fmQlifUjGkrJdHY&e= >> > _______________________________________________ > Ifeffit mailing list > Ifeffit@millenia.cars.aps.anl.gov > https://urldefense.proofpoint.com/v2/url?u=http-3A__millenia > .cars.aps.anl.gov_mailman_listinfo_ifeffit&d=CwICAg&c=-d > g2m7zWuuDZ0MUcV7Sdqw&r=UZ6LahCCy9yRGAvO8QDSWFzQq7a3vkDZfWzr2 > SslhiE&m=0g-Qe_mvavdjZMlwuLL_XAVOn-Hdw7MVoGFBObqHUUA&s= > y4QQn_F6Rx9uwWVg4Z7oYxHOx_7ddARSk12pRgTuM3o&e= Unsubscribe: > https://urldefense.proofpoint.com/v2/url?u=http-3A__millenia > .cars.aps.anl.gov_mailman_options_ifeffit&d=CwICAg&c=-dg > 2m7zWuuDZ0MUcV7Sdqw&r=UZ6LahCCy9yRGAvO8QDSWFzQq7a3vkDZfWzr2S > slhiE&m=0g-Qe_mvavdjZMlwuLL_XAVOn-Hdw7MVoGFBObqHUUA&s=6Tqa > DHnrgY2yWI_fJuteI2BzDNW0fmQlifUjGkrJdHY&e=
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