Hi Bruce, I agree with your comments. Side phase with less than 5% in total composition cannot be easily detected using regular XRD but comprehensively using EXAFS. Here, i have also recorded bulk sample, similar to nanoparticles composition, which is completely free from contamination. >From this data, i have ruled out the presence of heavy metals.
Regards, Raj On 4 January 2017 at 12:38, <ifeffit-requ...@millenia.cars.aps.anl.gov> wrote: > 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-requ...@millenia.cars.aps.anl.gov > > You can reach the person managing the list at > ifeffit-ow...@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. Re: Ifeffit Digest, Vol 167, Issue 2 (Raj kumar) > 2. Re: Ifeffit Digest, Vol 167, Issue 2 (Bruce Ravel) > 3. Re: Ifeffit Digest, Vol 167, Issue 2 (Raj kumar) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Tue, 3 Jan 2017 21:32:51 +0100 > From: Raj kumar <rajr...@gmail.com> > To: ifeffit@millenia.cars.aps.anl.gov > Subject: Re: [Ifeffit] Ifeffit Digest, Vol 167, Issue 2 > Message-ID: > <CACc-a9+uy+4i65LrZf8kiJRk6bdTD2cVSdeeGLp2r0x4fDBrSQ@mail. > gmail.com> > Content-Type: text/plain; charset="utf-8" > > Hi Scott, > > Thank you very much for your prompt response. EXAFS measurement was done > after the XRD characterization. From XRD, it is confirmed that there is no > side phase formation and contamination. Hence, i guess the heavier element > role could be avoided here. > > Split distances could be the reason??. The following is the method, i have > opted for modelling the obtained curve. Since YbVO4 is zircon structure, i > have constrained distance in paths 3, 8 and 9 with the pre-structural info > and let other distances vary with regular mathematical expression > alpha*Reff. am i doing wrong here? Before this, I have tried alpha*Reff for > all paths but fit failed miserably for multi-shells. > > Regards, > Raj > > On 3 January 2017 at 19:00, <ifeffit-requ...@millenia.cars.aps.anl.gov> > wrote: > > > 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-requ...@millenia.cars.aps.anl.gov > > > > You can reach the person managing the list at > > ifeffit-ow...@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. Re: Problem with large so2 (Scott Calvin) > > > > > > ---------------------------------------------------------------------- > > > > Message: 1 > > Date: Tue, 3 Jan 2017 09:59:18 -0600 > > From: Scott Calvin <dr.scott.cal...@gmail.com> > > To: XAFS Analysis using Ifeffit <ifeffit@millenia.cars.aps.anl.gov> > > Subject: Re: [Ifeffit] Problem with large so2 > > Message-ID: <3ef5e209-7681-49c6-9713-4bbf34c61...@gmail.edu> > > Content-Type: text/plain; charset="utf-8" > > > > Hi Raj, > > > > I haven?t looked at your files, but the kinds of results you are > > describing often indicate the model you are using beyond the first shell > is > > incorrect. It may be that it has the wrong elements (e.g., heavier > elements > > are present than what you modelled) or that the model includes split > > distances when in reality the compound is more symmetric. > > > > In short, no, the high second S02 does not make sense (although it would > > be good to know the uncertainties). > > > > Best, > > Scott Calvin > > Lehman College of the City University of New York > > > > > On Jan 3, 2017, at 9:38 AM, Raj kumar <rajr...@gmail.com> wrote: > > > > > > Dear All, > > > > > > > > > > > > I have been trying to fit EXAFS signal of YbVO4 both in bulk and > > nanoparticles form. Here, I would like to estimate so2 from bulk > > (reference) and subsequently use the number, as normalization parameter, > to > > calculate the co-ordination number in all nanoparticles. Nanoparticles > were > > synthesized by solution route. From our earlier understanding on the > > synthesis, in some cases, Yb may or may not completely involve in > reaction. > > Therefore, I except Yb in two environments, one surrounded by mere oxygen > > (in precise oxygen-Hydrogen; due to disorder one may expect a single > peak) > > and another one in YbVO4 environment. With this info and for reasonable > > fit, I have used two so2 as free parameters for N: one for first shell > > (oxygen at two distances) and another for rest other shells. If I use > > single so2, I obtain the value of around 0.92 with unsatisfactory fit > > whereas the fit seems plausible with two so2 i.e., 0.75 and 2.2, > > respectively. Using the same strategy, I could successfully fi! > > t the nanoparticles again with large second so2 (1.79). From literature > > and IFEFFIT earlier discussion, i understood that so2 should be between > > 0.8-1.2 value. Here, I would like to know, does this huge second so2 > value > > makes sense? is the obtained so2 value can be used to calculated > > coordination number for unknown? Further, i have attached my worked files > > with this message. > > > > > > > > > > > > Regards, > > > > > > Raj > > > > > > <YbVO4-bulk.fpj><YbVO4-nps.fpj>_____________________________ > > __________________ > > > 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 > > > > -------------- next part -------------- > > An HTML attachment was scrubbed... > > URL: <http://millenia.cars.aps.anl.gov/pipermail/ifeffit/attachme > > nts/20170103/adeb2d34/attachment-0001.html> > > > > ------------------------------ > > > > Subject: Digest Footer > > > > _______________________________________________ > > 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 > > > > > > ------------------------------ > > > > End of Ifeffit Digest, Vol 167, Issue 2 > > *************************************** > > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: <http://millenia.cars.aps.anl.gov/pipermail/ifeffit/attachme > nts/20170103/5fcf413e/attachment-0001.html> > > ------------------------------ > > Message: 2 > Date: Tue, 3 Jan 2017 15:45:37 -0500 > From: Bruce Ravel <bra...@bnl.gov> > To: XAFS Analysis using Ifeffit <ifeffit@millenia.cars.aps.anl.gov> > Subject: Re: [Ifeffit] Ifeffit Digest, Vol 167, Issue 2 > Message-ID: <d24675d6-264a-7850-54bd-109fe393b...@bnl.gov> > Content-Type: text/plain; charset=windows-1252; format=flowed > > On 01/03/2017 03:32 PM, Raj kumar wrote: > > From XRD, it is confirmed that there is no side phase formation and > > contamination. Hence, i guess the heavier element role could be avoided > > here. > > Raj, > > While this might be true for your sample, in general, a statement like > this always concerns me. > > From XRD, you can say is that there is no /crystalline/ side phase > formation and that there is no contamination in the /diffracting/ > /portion/ of the sample. > > It is very common when preparing nanoparticulate matter for there to be > non- or poorly-diffracting content in the sample. If that content > contains the absorbing element, then it will have an impact on the XAS > data. > > B > > > > -- > Bruce Ravel ------------------------------------ bra...@bnl.gov > > National Institute of Standards and Technology > Synchrotron Science Group at NSLS-II > Building 743, Room 114 > Upton NY, 11973 > > Homepage: http://bruceravel.github.io/home/ > Software: https://github.com/bruceravel > Demeter: http://bruceravel.github.io/demeter/ > > > ------------------------------ > > Message: 3 > Date: Wed, 4 Jan 2017 12:38:05 +0100 > From: Raj kumar <rajr...@gmail.com> > To: ifeffit@millenia.cars.aps.anl.gov > Subject: Re: [Ifeffit] Ifeffit Digest, Vol 167, Issue 2 > Message-ID: > <CACc-a9+EHP7bGjjpxW+cUp=9LzSZzKG=TvnM+gYVeR-T2g1yqQ@mail. > gmail.com> > Content-Type: text/plain; charset="utf-8" > > Hi Scott, > > I would like to add an extra point to the previous message. Yes, i am > getting a large uncertainty for the second so2 (2.04 +/- 1.36). > > Regards, > Raj > > On 3 January 2017 at 21:32, Raj kumar <rajr...@gmail.com> wrote: > > > Hi Scott, > > > > Thank you very much for your prompt response. EXAFS measurement was done > > after the XRD characterization. From XRD, it is confirmed that there is > no > > side phase formation and contamination. Hence, i guess the heavier > element > > role could be avoided here. > > > > Split distances could be the reason??. The following is the method, i > have > > opted for modelling the obtained curve. Since YbVO4 is zircon structure, > i > > have constrained distance in paths 3, 8 and 9 with the pre-structural > info > > and let other distances vary with regular mathematical expression > > alpha*Reff. am i doing wrong here? Before this, I have tried alpha*Reff > for > > all paths but fit failed miserably for multi-shells. > > > > Regards, > > Raj > > > > On 3 January 2017 at 19:00, <ifeffit-requ...@millenia.cars.aps.anl.gov> > > wrote: > > > >> 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-requ...@millenia.cars.aps.anl.gov > >> > >> You can reach the person managing the list at > >> ifeffit-ow...@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. Re: Problem with large so2 (Scott Calvin) > >> > >> > >> ---------------------------------------------------------------------- > >> > >> Message: 1 > >> Date: Tue, 3 Jan 2017 09:59:18 -0600 > >> From: Scott Calvin <dr.scott.cal...@gmail.com> > >> To: XAFS Analysis using Ifeffit <ifeffit@millenia.cars.aps.anl.gov> > >> Subject: Re: [Ifeffit] Problem with large so2 > >> Message-ID: <3ef5e209-7681-49c6-9713-4bbf34c61...@gmail.edu> > >> Content-Type: text/plain; charset="utf-8" > >> > >> Hi Raj, > >> > >> I haven?t looked at your files, but the kinds of results you are > >> describing often indicate the model you are using beyond the first > shell is > >> incorrect. It may be that it has the wrong elements (e.g., heavier > elements > >> are present than what you modelled) or that the model includes split > >> distances when in reality the compound is more symmetric. > >> > >> In short, no, the high second S02 does not make sense (although it would > >> be good to know the uncertainties). > >> > >> Best, > >> Scott Calvin > >> Lehman College of the City University of New York > >> > >> > On Jan 3, 2017, at 9:38 AM, Raj kumar <rajr...@gmail.com> wrote: > >> > > >> > Dear All, > >> > > >> > > >> > > >> > I have been trying to fit EXAFS signal of YbVO4 both in bulk and > >> nanoparticles form. Here, I would like to estimate so2 from bulk > >> (reference) and subsequently use the number, as normalization > parameter, to > >> calculate the co-ordination number in all nanoparticles. Nanoparticles > were > >> synthesized by solution route. From our earlier understanding on the > >> synthesis, in some cases, Yb may or may not completely involve in > reaction. > >> Therefore, I except Yb in two environments, one surrounded by mere > oxygen > >> (in precise oxygen-Hydrogen; due to disorder one may expect a single > peak) > >> and another one in YbVO4 environment. With this info and for reasonable > >> fit, I have used two so2 as free parameters for N: one for first shell > >> (oxygen at two distances) and another for rest other shells. If I use > >> single so2, I obtain the value of around 0.92 with unsatisfactory fit > >> whereas the fit seems plausible with two so2 i.e., 0.75 and 2.2, > >> respectively. Using the same strategy, I could successfully fi! > >> t the nanoparticles again with large second so2 (1.79). From literature > >> and IFEFFIT earlier discussion, i understood that so2 should be between > >> 0.8-1.2 value. Here, I would like to know, does this huge second so2 > value > >> makes sense? is the obtained so2 value can be used to calculated > >> coordination number for unknown? Further, i have attached my worked > files > >> with this message. > >> > > >> > > >> > > >> > Regards, > >> > > >> > Raj > >> > > >> > <YbVO4-bulk.fpj><YbVO4-nps.fpj>_____________________________ > >> __________________ > >> > 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 > >> > >> -------------- next part -------------- > >> An HTML attachment was scrubbed... > >> URL: <http://millenia.cars.aps.anl.gov/pipermail/ifeffit/attachme > >> nts/20170103/adeb2d34/attachment-0001.html> > >> > >> ------------------------------ > >> > >> Subject: Digest Footer > >> > >> _______________________________________________ > >> 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 > >> > >> > >> ------------------------------ > >> > >> End of Ifeffit Digest, Vol 167, Issue 2 > >> *************************************** > >> > > > > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: <http://millenia.cars.aps.anl.gov/pipermail/ifeffit/attachme > nts/20170104/7300fa88/attachment.html> > > ------------------------------ > > Subject: Digest Footer > > _______________________________________________ > 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 > > > ------------------------------ > > End of Ifeffit Digest, Vol 167, Issue 3 > *************************************** >
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