Re: [Ifeffit] XANES temperature estimation (Robert Gordon)
Hi Gabriele, On Mon, Nov 21, 2022 at 12:59 PM Gabriele Garofalo < gabriele.garof...@esrf.fr> wrote: > Hi Gordon, > > I have just one spectrum per sample, all taken at different T (unknown, > due to technical problems) and P (known). I'd like to find T and using > an EoS is not a viable option. > I was thinking that maybe, assuming that the Debye-Waller term is > explained only by thermal disorder, the Debye temperature is P > independent, and there are no structural or electronic transformations, > I could retrieve T by fitting the Debye-Waller term and using the > reference spectra. Is this possible? > It seems unlikely to me. XANES is typically described as probing the electronic states of a sample. There is, of course, a strong connection between atomic/nuclear structure and electronic structure, but the changes in thermal structural disorder with temperature are actually pretty small. Interference-sensitive measurements (EXAFS, XRD) will be sensitive to such changes, but XANES is much less so. When describing an EXAFS Deybe-Waller model, the amplitude decays as exp(-2k^2*sigma^2). When k is very small (ie, XANES), you need to have sigma be very large for that to make much of an impact in the XANES region. Some XANES features (such as pre-edge peak intensities) can have some temperature dependence - these are sensitive to small changes in the overlap of specific electronic levels. But, in general, the XANES features don't have a strong temperature dependence. But, I guess we should ask: do you see a significant variation in your XANES spectra with temperature? --Matt ___ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit
Re: [Ifeffit] XANES temperature estimation (Robert Gordon)
Hi Gordon, I have just one spectrum per sample, all taken at different T (unknown, due to technical problems) and P (known). I'd like to find T and using an EoS is not a viable option. I was thinking that maybe, assuming that the Debye-Waller term is explained only by thermal disorder, the Debye temperature is P independent, and there are no structural or electronic transformations, I could retrieve T by fitting the Debye-Waller term and using the reference spectra. Is this possible? Best regards Gabriele -- Message: 1 Date: Mon, 21 Nov 2022 16:16:50 +0100 From: Gabriele GAROFALO To: ifeffit@millenia.cars.aps.anl.gov Subject: [Ifeffit] XANES temperature estimation Message-ID: <0ce690cc-ca47-5507-76b3-848bba8d7...@esrf.fr> Content-Type: text/plain; charset=UTF-8; format=flowed Hi everyone, I'd like to estimate the temperature of some samples from some XANES spectra, is there a way to do that? I couldn't find an answer in the mailing list archive. Thanks! -- Message: 2 Date: Mon, 21 Nov 2022 10:23:10 -0500 From: Anatoly Frenkel To: XAFS Analysis using Ifeffit Subject: Re: [Ifeffit] XANES temperature estimation Message-ID: Content-Type: text/plain; charset=utf-8 Only evaporation temperature, when XANES spectrum disappears?:) Anatoly On Nov 21, 2022, at 10:20 AM, Gabriele GAROFALO wrote: ?Hi everyone, I'd like to estimate the temperature of some samples from some XANES spectra, is there a way to do that? I couldn't find an answer in the mailing list archive. Thanks! ___ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit -- Message: 3 Date: Mon, 21 Nov 2022 09:13:19 -0800 From: Robert Gordon To: XAFS Analysis using Ifeffit Subject: Re: [Ifeffit] XANES temperature estimation Message-ID: Content-Type: text/plain; charset="utf-8" Hi Gabriele, To qualify Anatoly's cheerful, pre-morning coffee response, if your samples are part of a sequence of measurements of a material whose XANES has been measured at different temperatures, and said XANES does have some changes owing to changes in physical or electronic behavior with temperature (i.e. a phase transition), then you could estimate where your samples fit within that determined behavior. Are you familiar with how temperature dependence manifests in a typical XAFS measurement? ...through the Debye-Waller term..the effects of which become less pronounced at lower k... Temperature is more typically a controlled parameter during measurements. So no, not really...unless there is a known behavior for comparison. -R. ___ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit
Re: [Ifeffit] XANES temperature estimation
Hi Gabriele, To qualify Anatoly's cheerful, pre-morning coffee response, if your samples are part of a sequence of measurements of a material whose XANES has been measured at different temperatures, and said XANES does have some changes owing to changes in physical or electronic behavior with temperature (i.e. a phase transition), then you could estimate where your samples fit within that determined behavior. Are you familiar with how temperature dependence manifests in a typical XAFS measurement? ...through the Debye-Waller term..the effects of which become less pronounced at lower k... Temperature is more typically a controlled parameter during measurements. So no, not really...unless there is a known behavior for comparison. -R. On Mon, Nov 21, 2022 at 7:23 AM Anatoly Frenkel < anatoly.fren...@stonybrook.edu> wrote: > Only evaporation temperature, when XANES spectrum disappears…:) > > Anatoly > > > On Nov 21, 2022, at 10:20 AM, Gabriele GAROFALO < > gabriele.garof...@esrf.fr> wrote: > > > > Hi everyone, > > > > I'd like to estimate the temperature of some samples from some XANES > spectra, is there a way to do that? I couldn't find an answer in the > mailing list archive. > > > > Thanks! > > > > ___ > > Ifeffit mailing list > > Ifeffit@millenia.cars.aps.anl.gov > > http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit > > Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit > > ___ > Ifeffit mailing list > Ifeffit@millenia.cars.aps.anl.gov > http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit > Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit > ___ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit
Re: [Ifeffit] XANES temperature estimation
Only evaporation temperature, when XANES spectrum disappears…:) Anatoly > On Nov 21, 2022, at 10:20 AM, Gabriele GAROFALO > wrote: > > Hi everyone, > > I'd like to estimate the temperature of some samples from some XANES spectra, > is there a way to do that? I couldn't find an answer in the mailing list > archive. > > Thanks! > > ___ > Ifeffit mailing list > Ifeffit@millenia.cars.aps.anl.gov > http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit > Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit ___ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit
[Ifeffit] XANES temperature estimation
Hi everyone, I'd like to estimate the temperature of some samples from some XANES spectra, is there a way to do that? I couldn't find an answer in the mailing list archive. Thanks! ___ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit
