Re: [Ifeffit] Peakfitting CeO2 data in Athena

Thank you Matthew and Matt for your responses. Sorry if these are silly questions...so then does that mean arctan and gaussian shouldn't be used together? What was meant by "it does not inherently include any understanding of what that peak is"? That these functions aren't representative of the

Re: [Ifeffit] Peakfitting CeO2 data in Athena

The usual justification for using gaussians for peaks, aside from "it works" is that there's inhomogeneous broadening over and above the lifetime. The usual justification for using an arctan for the step is exactly the opposite. Instrument broadening is often taken to be gaussian. Net result:

Re: [Ifeffit] Peakfitting CeO2 data in Athena

Hi Stephanie, On Wed, Dec 7, 2016 at 12:33 PM, 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

Re: [Ifeffit] Peakfitting CeO2 data in Athena

Ce(OH)4 is probably not a well-defined compound. I wouldn't use it. I suspect that "Ce(OH)4" is really hydrated CeO2 nanos. I've measured 30nm CeO2 nanos and they look like bulk. mam On 12/7/2016 11:53 AM, Stephanie Laga wrote: I had started with LSQ but switched to peak fitting

Re: [Ifeffit] Peakfitting CeO2 data in Athena

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

Re: [Ifeffit] Peakfitting CeO2 data in Athena

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

[Ifeffit] Peakfitting CeO2 data in Athena

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