scaling factor in JDY3?
Dear all, I came up with a question about the magnetic form factor of Dy3+ ion. If I calculate it using seven coefficients (A,a,B,b,C,c,D) contained in a internal table of FullProf with a label JDY3, I get a value larger than 1 at x=sin(theta)/lambda=0. To my (little) knowledge, magnetic form factors should be 1 at x=0 because j0(0)=1 and j2(0)=0. I have compared the magnetic form factor of Dy3+ with the one calculated from the coefficient sets in International Tables for Crystallography (2006). Vol. C, Section 4.4.5 with a formula j0+gL/g*j2, and I got a scaling factor 1.132 between the two curves. For the case of Nd3+, it is confirmed that coefficient sets of JND3 and ITC give almost same values. Here is a link for a picture which summarizes my question. https://www.dropbox.com/s/8zgqdeqymbk4qla/magnetic_form_factor_of_Dy_Nd.png Note that JDY3 curve(blue) and scaled ITC curve(light blue) does not agree well in high Q range. This also puzzles me. Do you have any ideas? By the way, is there any way to look into the internal table of form factors in FullProf? I know that I can find seven-coefficients sets used in a calculation in .out file but I would like to make a list of the coefficient sets available in FullProf. Thanks in advance. Best, Kotaro ////// Kotaro SAITO High Energy Accelerator Research Organization Institute of Materials Structure Science 1-1 Oho, Tsukuba, Ibaraki, 305-0801, Japan ////// ++ Please do NOT attach files to the whole list Send commands to eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/ ++
Re: scaling factor in JDY3?
Jens, Thank you for the answer. This is exactly what I want. I should have looked into the documentations on the website... Best, Kotaro On 2013/09/25, at 22:41, Jens Hunger wrote: > On Wed, 25 Sep 2013 12:33:47 +0200 > Kotaro SAITO wrote: > >> By the way, is there any way to look into the internal table of form >> factors in FullProf? I know that I can find seven-coefficients sets >> used in a calculation in .out file but I would like to make a list of >> the coefficient sets available in FullProf. > > Since FullProf is based on CrysFML, the form factors should be the same > as in > https://forge.epn-campus.eu/projects/crysfml/repository/entry/Src/CFML_Chem_Scatt.f90 > > Cheers, > Jens. > ++ > Please do NOT attach files to the whole list > Send commands to eg: HELP as the subject with no body text > The Rietveld_L list archive is on > http://www.mail-archive.com/rietveld_l@ill.fr/ > ++ > ++ Please do NOT attach files to the whole list Send commands to eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/ ++
strange behavior in simulation of FullProf?
Dear all, I found something strange when I was checking simulated magnetic intensities of a tetragonal ferromagnetic compound using FullProf with Jbt=-3, Isy=-2 or -1. Without any change in a pcr file, calculated magnetic intensities in the .out file vary every time I run FullProf. In addition, sometimes some peaks which should have identical intensity due to symmetry have different intensities. Here is an example of 200 reflection. All calculations were done without any change in the pcr file. tetragonal ferromagnet, magnetic moment//c-axis hklIcalc 0 2 0 44.2 2 0 0 44.2 0 2 0 30.8 2 0 0 30.8 0 2 0 35.4 2 0 0 34.6 0 2 0 51.9 2 0 0 51.9 0 2 0 32.7 2 0 0 30.8 0 2 0 43.0 2 0 0 51.9 After many attempts, I can say 30.8 may be the most frequent value for 200 and 020 reflection. I use FullProf.2k Version 5.30 - Mar2012 on Mac. Does anyone have a idea to avoid this behavior? Best, Kotaro ////// Kotaro SAITO High Energy Accelerator Research Organization Institute of Materials Structure Science 1-1 Oho, Tsukuba, Ibaraki, 305-0801, Japan ////// ++ Please do NOT attach files to the whole list Send commands to eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/ ++
Re: strange behavior in simulation of FullProf?
Dear Pawel, Rietvelders Thank you for your response. I have got no reply from FullProf developers yet. I found this phenomenon on the latest version of FullProf Suite for Mac called September-2014 on the website and also called Version 5.30 - Mar2012 in the FullProf Program window. I have also confirmed same phenomenon on FullProf for Windows, December-2014 on the website, Version 5.30 - Mar2012 in the FullProf Program window. Here is a pcr file for checking the phenomenon. I also prepared dummy.dat to run the file because I don’t know how to run a pcr file for multiple patterns without data file. https://www.dropbox.com/s/szhu3hymd80tbuw/different_simulation_results.pcr?dl=0 https://www.dropbox.com/s/9a4gwxpkrryevqs/dummy.dat?dl=0 Regards, Kotaro ////// Kotaro SAITO High Energy Accelerator Research Organization Institute of Materials Structure Science 1-1 Oho, Tsukuba, Ibaraki, 305-0801, Japan ////// > 2014/12/05 23:10、Paweł Zajdel のメール： > > Dear Kotaro, > > Have you got any reply ffrom Fullprof people? > Can you prepare a pcr file, which can be used by others to check your > observation? > Does the problem apprear also in the last version of Fullprof? > > Regards > Pawel > On 2014-12-03 07:43, Kotaro SAITO wrote: >> Dear all, >> >> I found something strange when I was checking simulated magnetic intensities >> of a tetragonal ferromagnetic compound using FullProf with Jbt=-3, Isy=-2 >> or -1. >> Without any change in a pcr file, calculated magnetic intensities in the >> .out file vary every time I run FullProf. >> In addition, sometimes some peaks which should have identical intensity due >> to symmetry have different intensities. >> Here is an example of 200 reflection. All calculations were done without any >> change in the pcr file. >> >> tetragonal ferromagnet, magnetic moment//c-axis >> hklIcalc >> 0 2 0 44.2 >> 2 0 0 44.2 >> >> 0 2 0 30.8 >> 2 0 0 30.8 >> >> 0 2 0 35.4 >> 2 0 0 34.6 >> >> 0 2 0 51.9 >> 2 0 0 51.9 >> >> 0 2 0 32.7 >> 2 0 0 30.8 >> >> 0 2 0 43.0 >> 2 0 0 51.9 >> >> After many attempts, I can say 30.8 may be the most frequent value for 200 >> and 020 reflection. >> I use FullProf.2k Version 5.30 - Mar2012 on Mac. >> Does anyone have a idea to avoid this behavior? >> >> Best, >> Kotaro >> >> ////// >> Kotaro SAITO >> High Energy Accelerator Research Organization >> Institute of Materials Structure Science >> 1-1 Oho, Tsukuba, Ibaraki, 305-0801, Japan >> ////// >> > > -- > dr Pawel Zajdel > Institute of Physics > University of Silesia > Uniwersytecka 4 > 40-007 Katowice > Polska/Poland > [++48]323591978 > ++ Please do NOT attach files to the whole list Send commands to eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/ ++
Quantitative phase analysis on FullProf
Dear Rietvelders, Does anyone know how FullProf calculates weight fractions “Fract(%)” in a .sum file? or Is there any known bugs for calculating ATZ? According to the manual, it seems that ATZ is used for calculating the values... but no further information is written in the manual. I am also wondering, in my case, why different phases have the exact same value for ATZ. It should be different for different materials from the definition in the manual. Here are the related descriptions in my .out file. Phase 1 => The given value of ATZ is688.48 the program has calculated: 4345.96 Phase 2 => The given value of ATZ is688.48 the program has calculated: 576.91 I confirmed that 4345.96 and 576.91 seem to be Z*Mw I calculated the weight fractions using the values in the sum file and a equation Wp=S_p(ZMV)_p/ΣS_i(ZMV)_i (R. J. Hill and C. J. Howard, J Appl. Cryst., 20, 467-474), and ended up in getting quite different fractions from those in the .sum file. I got 97.3% and 2.7% with my calculation and the values in the .sum file are like this. Phase 1 => Bragg R-factor: 2.74 Vol: 941.374( 0.009) Fract(%): 82.46( 0.85) => Rf-factor= 1.81 ATZ: 688.475 Brindley: 1. Phase 2 => Bragg R-factor: 7.65 Vol: 137.093( 0.079) Fract(%): 17.54( 0.97) => Rf-factor= 5.35 ATZ: 688.475 Brindley: 1. When I ran an example pcr for quantitative phase analysis in Examples (si3n4r.pcr), I got ATZ and weight fractions below Si3N4 alpha => The given value of ATZ is560.00 the program has calculated: 561.14 Si3N4 beta => The given value of ATZ is280.00 the program has calculated: 280.57 => Phase: 1 Si3 N4 alpha => Bragg R-factor: 0.969 Vol: 292.623( 0.016) Fract(%): 92.88( 0.44) => Rf-factor= 0.600 ATZ: 560.000 Brindley: 1. => Phase: 2 Si3 N4 beta => Bragg R-factor: 2.26 Vol: 145.711( 0.027) Fract(%):7.12( 0.09) => Rf-factor= 1.09 ATZ: 280.000 Brindley: 1. and the these fractions are consistent with those derived from the equation Wp=S_p(ZMV)_p/ΣS_i(ZMV)_i. I would like to know which weight fractions I should trust for my case… Best regards, Kotaro //========//// Kotaro SAITO High Energy Accelerator Research Organization Institute of Materials Structure Science 1-1 Oho, Tsukuba, Ibaraki, 305-0801, Japan ////// ++ Please do NOT attach files to the whole list Send commands to eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/ ++
Re: Quantitative phase analysis on FullProf
Thank you all for kind replies. Following the advices, I ran FullProf putting ATZ=0 for both phases and I got the consistent weight fractions with my calculation using Wp=S_p(ZMV)_p/ΣS_i(ZMV)_i. Actually I found a description about ATZ=0 in fp2k.inf after getting replies. I am sorry for forgetting to do this before ask. I still can not get the idea of ATZ even after Carlos’s explanation "Atz is the mass of the unit cell in atomic units." What does “f”’ in the manual actually mean? and why is “f" squared in the definition of ATZ? I don’t understand what "their true value” is. > Carlos I always use Ns/Ng for occupancies because I was taught to do so. I thought everyone uses normalized occupancies but it seems I was wrong judging from your advice. > Patrick Thanks for the caution. That may relate to my case because one of the two phases contains substituted atoms. I found a description below in July 4th 2011 update of fp2k.inf. > - In the new version of FullProf the calculation of ATZ takes into account > the first and second > atom of the list. In a compound with all sites partially occupied, it is > supposed that the two > first atoms are in the same site and occupy fully the site. In this case > the value of ATZ is > correctly calculated. For my case, there are nine sites and two of those are occupied by two kinds of atoms (Nat=11). And I want to refine their occupancies to know the site preference. The two sites are placed in the head of the atom list like below. !Atom … Occ A1 … 0.22000 B1 … 0.03000 A2 … 0.22000 B2 … 0.03000 C … D … Occupancies for site 1 and site 2 are set to maintain the normalized occupancy 0.25 using codewords. I think this does not violate your caution and the description in fp2k.inf. Maybe I should not ask why (only?) the first atom needs to be fully occupied… ////// Kotaro SAITO High Energy Accelerator Research Organization Institute of Materials Structure Science 1-1 Oho, Tsukuba, Ibaraki, 305-0801, Japan ////// > > > From: rietveld_l-requ...@ill.fr [mailto:rietveld_l-requ...@ill.fr] On Behalf > Of Kotaro SAITO > Sent: den 24 februari 2015 11:53 > To: Rietveld_l@ill.fr > Subject: Quantitative phase analysis on FullProf > > Dear Rietvelders, > > Does anyone know how FullProf calculates weight fractions “Fract(%)” in a > .sum file? or Is there any known bugs for calculating ATZ? > > According to the manual, it seems that ATZ is used for calculating the > values... but no further information is written in the manual. > I am also wondering, in my case, why different phases have the exact same > value for ATZ. It should be different for different materials from the > definition in the manual. > Here are the related descriptions in my .out file. > Phase 1 > => The given value of ATZ is688.48 the program has > calculated:4345.96 > Phase 2 > => The given value of ATZ is688.48 the program has > calculated: 576.91 > I confirmed that 4345.96 and 576.91 seem to be Z*Mw > > I calculated the weight fractions using the values in the sum file and a > equation Wp=S_p(ZMV)_p/ΣS_i(ZMV)_i (R. J. Hill and C. J. Howard, J Appl. > Cryst., 20, 467-474), and ended up in getting quite different fractions from > those in the .sum file. I got 97.3% and 2.7% with my calculation and the > values in the .sum file are like this. > Phase 1 > => Bragg R-factor: 2.74 Vol: 941.374( 0.009) Fract(%): > 82.46( 0.85) > => Rf-factor= 1.81 ATZ: 688.475 Brindley: > 1. > Phase 2 > => Bragg R-factor: 7.65 Vol: 137.093( 0.079) Fract(%): > 17.54( 0.97) > => Rf-factor= 5.35 ATZ: 688.475 Brindley: > 1. > > > When I ran an example pcr for quantitative phase analysis in Examples > (si3n4r.pcr), I got ATZ and weight fractions below > Si3N4 alpha > => The given value of ATZ is560.00 the program has calculated: > 561.14 > Si3N4 beta > => The given value of ATZ is280.00 the program has calculated: > 280.57 > > => Phase: 1 Si3 N4 alpha > => Bragg R-factor: 0.969 Vol: 292.623( 0.016) Fract(%): 92.88( > 0.44) > => Rf-factor= 0.600 ATZ: 560.000 Brindley: 1. > > => Phase: 2 Si3 N4 beta > => Bragg R-factor: 2.26 Vol: 145.711( 0.027) Fract(%):7.12( > 0.09) > => Rf-factor= 1.09 ATZ: 280.000 Brindley: 1.0000 > > and the these fractions are consistent with those derived from the equation > Wp=S_p(ZMV)_p/
Selective peak broadening - interpretation and handling in FullProf
Dear Rietvelders, There is two things I would like to ask. 1. Physical interpretation of selective peak broadening I have a difficulty in interpreting selective peak broadening in my TOF data of quaternary Heusler alloy. All peaks for all-odd hkl reflections show significant broadening (about 25% increase from the instrumental resolution for small d range and 100% increase for large d range). Other peaks for all-even hkl stay in the instrumental resolution for whole d range. If hkl reflections for one specific direction show broadening, it might be easier to interpret. But this time, it is not the case. (eg. 111 reflection shows significant broadening but 222 does not.) If I write the sample's chemical formula as ABCD, 4 sites in the Heusler alloy along [111] direction seems to be (A,B)-(C,D)-(C,D)-(A,B) with different site mixing ratio according to brief analysis. One thing I have noticed is that each lattice plane for all-odd hkl consists of one sublattice. For the case of 111 reflection, which is the easiest case, first plane at the origin consists only (A,B). Second plane consists only (C,D), and so on. This holds for other all-odd hkl reflections Does anyone know good literatures to get some hints for this? I have checked “Defect and Microstructure Analysis by Diffraction” by Snyder, Fiala, and Bunge, but I couldn’t find descriptions about selective peak broadening. 2. Handling selective peak broadening in FullProf The manual says “there is a number of size models built into FullProf corresponding to particular sets of reflections that are affected from broadening.” But I only find Size-Model=14 and -2 (to -9) in the manual for that purpose. Are there any models other than these? And, does anyone know what Size-Model=14 is? The manual only shows a result using Size-Model=14 (Figure 2) without any explanations. I have already tried Size-Model=-2 and it works well but not sufficient for 111 peak which shows the largest broadening. (and it does not gives me any physical interpretation, of course.) Best, Kotaro ////// Kotaro SAITO High Energy Accelerator Research Organization Institute of Materials Structure Science 1-1 Oho, Tsukuba, Ibaraki, 305-0801, Japan ////// ++ Please do NOT attach files to the whole list Send commands to eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/ ++
Re: Selective peak broadening - interpretation and handling in FullProf
Dear Radovan and Leonid, Thanks for your comments. Both papers are very interesting and seem to contain good hints for my case. Now I am confusing when I compare peak width vs. 2th in constant wave profiles and peak width vs. d in TOF. When I plot FWHM/d vs. d, FWHM/d of all-odd peaks increases with increasing d. (Note these FWHM are obtained with multiple peak fitting with simple Gaussian.) In other words, peak broadening is large for small hkl peaks. Here is the plot. (not an attachment file!) https://www.dropbox.com/s/uzm0fv3q8ljoq5o/Layout0.pdf?dl=0 On the other hand, for example Fig.3 in Leonid’s paper (http://dx.doi.org/10.1107/S00218898114X), peak broadening is larger for large 2th, which means large hkl peaks. If the peak broadening in my TOF data has a similar origin as two papers which Radovan and Leonid showed, is it acceptable to have such different hkl dependence between TOF and 2th data? Or do I miss some basic points about diffraction? Best regards, Kotaro ////// Kotaro SAITO High Energy Accelerator Research Organization Institute of Materials Structure Science 1-1 Oho, Tsukuba, Ibaraki, 305-0801, Japan ////// > 2015/07/31 17:13、Radovan Cerny のメール： > > Dear Kotaro, > > The same rule of line broadening was observed in beta phase of Mg(BH4)2, and > was explained as ordering of twin domains, in other words microtwinning which > creates a superstructure to the even,even,even subcell. If the twinning > probability is not 100%, then the odd,odd,odd reflections broaden till they > disappear. > You may find an inspiration in > > Acta Cryst. (2007). B63, 561-568[ doi:10.1107/S0108768107022665 ] > > Structure of unsolvated magnesium borohydride Mg(BH4)2 > > J.-H. Her, P. W. Stephens, Y. Gao, G. L. Soloveichik, J. Rijssenbeek, M. > Andrus and J.-C. Zhao > > > > In Fullprof there are few models of line broadening, but I do not know > whether any of them can be used for your case. In Topas you may create any > model of line broadening using the macro language. > > Hope it helps > > Radovan > > > Radovan Cerny > Laboratoire de Cristallographie, DQMP > Université de Genève > 24, quai Ernest-Ansermet > CH-1211 Geneva 4, Switzerland > Phone : [+[41] 22] 37 964 50, FAX : [+[41] 22] 37 961 08 > mailto : radovan.ce...@unige.ch > URL: http://www.unige.ch/sciences/crystal/cerny/rcerny.htm > > De : rietveld_l-requ...@ill.fr [mailto:rietveld_l-requ...@ill.fr] De la part > de Kotaro SAITO > Envoyé : vendredi 31 juillet 2015 09:15 > À : Rietveld_l@ill.fr > Objet : Selective peak broadening - interpretation and handling in FullProf > > Dear Rietvelders, > > There is two things I would like to ask. > > 1. Physical interpretation of selective peak broadening > I have a difficulty in interpreting selective peak broadening in my TOF data > of quaternary Heusler alloy. > All peaks for all-odd hkl reflections show significant broadening (about 25% > increase from the instrumental resolution for small d range and 100% increase > for large d range). > Other peaks for all-even hkl stay in the instrumental resolution for whole d > range. > If hkl reflections for one specific direction show broadening, it might be > easier to interpret. > But this time, it is not the case. (eg. 111 reflection shows significant > broadening but 222 does not.) > If I write the sample's chemical formula as ABCD, 4 sites in the Heusler > alloy along [111] direction seems to be (A,B)-(C,D)-(C,D)-(A,B) with > different site mixing ratio according to brief analysis. > One thing I have noticed is that each lattice plane for all-odd hkl consists > of one sublattice. > For the case of 111 reflection, which is the easiest case, first plane at the > origin consists only (A,B). Second plane consists only (C,D), and so on. > This holds for other all-odd hkl reflections > Does anyone know good literatures to get some hints for this? > I have checked “Defect and Microstructure Analysis by Diffraction” by Snyder, > Fiala, and Bunge, but I couldn’t find descriptions about selective peak > broadening. > > 2. Handling selective peak broadening in FullProf > The manual says “there is a number of size models built into FullProf > corresponding to particular sets of reflections that are affected from > broadening.” > But I only find Size-Model=14 and -2 (to -9) in the manual for that purpose. > Are there any models other than these? > And, does anyone know what Size-Model=14 is? > The manual only shows a result using Size-Model=14 (Figure 2) without any > explanations. > I have already tried Size-Model=-2
Re: Selective peak broadening - interpretation and handling in FullProf
> Alan and Maxim, Thanks for the comment and the article. I relieved that I know the point. > Leonid, Yes, the instrumental resolution itself increases with d (or TOF). But it is still strange for me that only all-odd peaks show different d-dependence from CeO2 and other all-even peaks in terms of slope in the delta-d/d vs d plot. Now, I think a similar situation as high temperature phase of Mg(BH4)2 occurs in my quaternary Heusler sample. For all-odd hkl, structure factor is F_hkl=4(f_A-f_C)+/-4i(f_B-f_D). Here, A-D denote four fcc sublattices in Heusler alloys, or 4a,4c,4b,4d sites in F-43m. If there exist ABCD and CDAB type domains, those domain have out-of-phase scattering for all-odd reflections and same story as Mg(BH4)2 can be applied. But still I don’t understand why peak widths show such strong dependence on d (or TOF). Concerning attachment files. This time I use Dropbox but I don’t guarantee it as an image archive because the image might be removed by me a few years later when I clean up my folders. ////====// Kotaro SAITO High Energy Accelerator Research Organization Institute of Materials Structure Science 1-1 Oho, Tsukuba, Ibaraki, 305-0801, Japan ////// > 2015/08/04 19:34、Alan Hewat のメール： > > On 4 August 2015 at 11:54, Kotaro SAITO wrote: > Or do I miss some basic points about diffraction? > > I won't try to address your specific material... and I'm being called to > lunch :-) But for beginners who may be lost in these technical papers, I will > attempt the following trivial explanation > > If you have a layered material where two layers A and B are slightly > different you will have super-structure reflections. These will be as sharp > as the main reflections (from the average structure) if the order of the > layers is perfectly regular ABABABAB... > > But if the layers only have short-range order eg ABABBABAAB... then these > superlattice reflections will be broadened, and even completely washed out if > the order between layers is completely random. Otherwise the width delta-d of > the superstructure reflections will give you the short range order length - > the shorter the correlation length the broader the superlattice reflections. > > Obviously delta-d doesn't depend on the d-spacing between layers, only on the > length of their order. So the broadening is constant in d-space as usually > plotted for TOF neutron diffraction. > > For angular dispersion eg with a constant x-ray or neutron wavelength, > Bragg's law 2d.sin(theta)=lambda comes in. If you differentiate Bragg's law > you will find a simple relation between delta-d and delta-2theta, the line > broadening for angular dispersion measurements. > > Alan. > (Everything should be as simple as possible... but no simpler.) > BTW, thanks for using dropbox instead of an attachment. That's the way to > go... > -- > __ >Dr Alan Hewat, NeutronOptics, Grenoble, FRANCE > +33.476.98.41.68 > http://www.NeutronOptics.com/hewat > __ > ++ > Please do NOT attach files to the whole list > Send commands to eg: HELP as the subject with no body text > The Rietveld_L list archive is on > http://www.mail-archive.com/rietveld_l@ill.fr/ > ++ > ++ Please do NOT attach files to the whole list Send commands to eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/ ++
Re: Selective peak broadening - interpretation and handling in FullProf
Dear Radovan and Rietvelders, I apologize for such late response. Here is a plot of FWHM vs 1/d. https://www.dropbox.com/s/ndn58ua1317bmhb/quat_Heusler_FWHM_1%3Ad_plot.pdf?dl=0 All-odd line is nicely shifted as Radovan suggested. According to microstructure analysis for CW method, the plot indicates that all peaks have a strain effect and all-odd peaks have stronger size effect than other peaks. But, is it allowed to apply the idea of FWHM vs.1/d plot both qualitatively and quantitatively to TOF data without any consideration? I am afraid that there would be pitfalls one should avoid. At least, I have noticed that I need to be careful about how to get peak width. In the plot above and the one I posted before, FWHMs are obtained by simple gaussian fitting of individual peak to check the broadening behavior qualitatively. If I want do quantitatively reliable microstructure analysis (I am not sure that there is an established method for TOF data yet), I should take into account rising and decay convolutions to get “real” peak width in addition to instrumental resolution. Then, if I converted TOF profiles into 1/d, I will be stuck because I cannot use a conventional analytical form of a convoluted peak shape function. Or just taking integral breadths is enough? I understand TOF is not suitable for microstructure analysis because peak shape is rather complicated than CW. This is also indicated by the fact that all of the explanations about microstructure analysis which I have read are based on CW and none of them mentioned about TOF. It was not a purpose of our measurement, but I just want to try to extract microstructure information from my TOF data. Best regards, Kotaro ////// Kotaro SAITO High Energy Accelerator Research Organization Institute of Materials Structure Science 1-1 Oho, Tsukuba, Ibaraki, 305-0801, Japan ////// > 2015/08/10 16:37、Radovan Cerny のメール： > > Dear Kotaro, > > I think that it is a good track to follow. Compared to Mg(BH4)2 you may have > also chemical order of your four elements ABCD on top of the coherent domains > ordering. Both are of course related. > The antiphase domain ordering is visible in line broadening as a size effect > which is constant in the scale 1/d. It means that it is not constant in the > scale d. Have you plotted your powder pattern in the scale 1/d? > > Best regards > > Radovan > > > Radovan Cerny > Laboratoire de Cristallographie, DQMP > Université de Genève > 24, quai Ernest-Ansermet > CH-1211 Geneva 4, Switzerland > Phone : [+[41] 22] 37 964 50, FAX : [+[41] 22] 37 961 08 > mailto : radovan.ce...@unige.ch > URL: http://www.unige.ch/sciences/crystal/cerny/rcerny.htm > > De : rietveld_l-requ...@ill.fr [mailto:rietveld_l-requ...@ill.fr] De la part > de Kotaro SAITO > Envoyé : vendredi 7 août 2015 09:49 > À : Alan Hewat; loba...@inorg348-1.chem.msu.ru; Rietveld_l@ill.fr; > l_solov...@yahoo.com > Objet : Re: Selective peak broadening - interpretation and handling in > FullProf > > > Alan and Maxim, > > Thanks for the comment and the article. > I relieved that I know the point. > > > Leonid, > Yes, the instrumental resolution itself increases with d (or TOF). > But it is still strange for me that only all-odd peaks show different > d-dependence from CeO2 and other all-even peaks in terms of slope in the > delta-d/d vs d plot. > > Now, I think a similar situation as high temperature phase of Mg(BH4)2 occurs > in my quaternary Heusler sample. > For all-odd hkl, structure factor is F_hkl=4(f_A-f_C)+/-4i(f_B-f_D). Here, > A-D denote four fcc sublattices in Heusler alloys, or 4a,4c,4b,4d sites in > F-43m. > If there exist ABCD and CDAB type domains, those domain have out-of-phase > scattering for all-odd reflections and same story as Mg(BH4)2 can be applied. > But still I don’t understand why peak widths show such strong dependence on d > (or TOF). > > Concerning attachment files. > This time I use Dropbox but I don’t guarantee it as an image archive because > the image might be removed by me a few years later when I clean up my folders. > > ////// > Kotaro SAITO > High Energy Accelerator Research Organization > Institute of Materials Structure Science > 1-1 Oho, Tsukuba, Ibaraki, 305-0801, Japan > ////// > > > 2015/08/04 19:34、Alan Hewat のメール： > > > > On 4 August 2015 at 11:54, Kotaro SAITO wrote: > > Or do I miss some basic points about diffraction? > > > > I won't try to address your specific material... and I'm being called to > > lunch :-) But for beginn
Re: NO REFLECTIONS FOUND -> Check your input data
Dear Kateryna, I don’t know the exact reason for the error, but it is always better to start with template pcr files in FullProf/Examples folder. You can find the summary of each pcr files in Examples/examples.txt. I think CeO2_PEARL.pcr or hrpd.pcr would be good templates to start with. At least you need to modify TOF coefficients(Zero ,dtt1, dtt2), peak profiles (Sig-2, Gam-2 , alpha, beta0, etc.) and phase parameters. Please do not forget to specify a path to your experimental data because somehow FullProf needs a valid path to an experimental data file even for simulation. Best regards, Kotaro ////// Kotaro SAITO High Energy Accelerator Research Organization Institute of Materials Structure Science 1-1 Oho, Tsukuba, Ibaraki, 305-0801, Japan ////// > 2016/08/20 2:04、foyevts...@phas.ubc.ca のメール： > > Dear Sudhindra, > > thank you for the suggestion! I am using cif, which is a format that > FullProf should support. > > Besides, using same cif file I can successfully generate a monochromatic > X-ray pattern. So, the problem has probably to do with the TOF, I guess. > > Best, > Kateryna > >> Hi, >> >> The error is likely to come from the format of your data file. you should >> follow one of the data formats which Fullprof can read. I think it is a >> minor error and it can be sorted out.. >> best, >> Sudhindra >> >> >> On 08/19/16 09:43 PM, foyevts...@phas.ubc.ca wrote: >>> >>> Hello, >>> >>> I am new to FullProf. I would like to use it to generate a neutron >>> Time-of-Flight diffraction pattern for a theoretical crystal structure >>> of >>> LiNiO2. >>> >>> I have the structural data in .cif format. I go through the following >>> steps: >>> >>> 1) Launch edpcr >>> 2) Templates -> Simple calculation >>> 3) Choose TOF and load POLARIS_ISIS.irf >>> 4) Import a cif file >>> 5) Ok >>> 6) Save >>> 7) Tools -> FullProf >>> >>> In the command line I see this message: >>> NO REFLECTIONS FOUND -> Check your input data >>> >>> However, in the generated *.out file, I find that >>> The number of reflections generated is: 2902 >>> >>> Please, help. >>> >>> Thank you, >>> Kateryna Foyevtsova >>> >>> ++ >>> Please do NOT attach files to the whole list >>> >>> Send commands to eg: HELP as the subject with no body >>> text >>> The Rietveld_L list archive is on >>> http://www.mail-archive.com/rietveld_l@ill.fr/ >>> ++ >>> >>> >>> >> -- >> Dr. Sudhindra Rayaprol >> Scientist - E >> UGC-DAE Consortium for Scientific Research >> Mumbai Centre >> R-5 Shed, BARC - Trombay >> Mumbai - 400085 >> INDIA >> > > ++ > Please do NOT attach files to the whole list > Send commands to eg: HELP as the subject with no body text > The Rietveld_L list archive is on > http://www.mail-archive.com/rietveld_l@ill.fr/ > ++ > ++ Please do NOT attach files to the whole list Send commands to eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/ ++
Making an unit cell with all sites occupied by multiple atoms in FullProf
Dear FullProf users, I would like to make a pcr file for a Heusler alloy with so-called A2 structure, in which three atoms are completely disordered. (See Fig.1 in http://dx.doi.org/10.1088/0022-3727/48/16/164011 or this direct link http://cdn.iopscience.com/images/0022-3727/48/16/164011/Full/jphysd500490f01_online.jpg) For example, a straightforward description of A2 Heusler alloy Co2FeSi would be like this. I m -3 m <--Space group symbol !Atom Typ XYZ Biso Occ In Fin N_t Spc /Codes Co Co 0.0 0.0 0.0 0.5 0.01041 0 0 00 0.00 0.00 0.00 0.00 0.00 Fe FE 0.0 0.0 0.0 0.5 0.00521 0 0 00 0.00 0.00 0.00 0.00 0.00 Si SI 0.0 0.0 0.0 0.5 0.00521 0 0 00 0.00 0.00 0.00 0.00 0.00 (general multiplicity = 96, multiplicity of (0,0,0) is 2, so Occ=0.02083 when fully occupied by one atom) But, as many of you know, FullProf assumes that "THE FIRST GIVEN SITE IS FULLY OCCUPIED OR THE FIRST AND SECOND ATOMS ARE IN THE SAME SITE WITH TOTAL FULL OCCUPATION (If this is not the case, change the order of atoms to obtain correct values for the content of the unit cell)” (quoted from a output file). Accordingly, a cif file generated after running of a pcr with the atomic position above shows unintended values as below. loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv _atom_site_occupancy _atom_site_adp_type # Not in version 2.0.1 _atom_site_type_symbol Co 0.0 0.0 0.0 0.00633 0.66645 Uiso Co Fe 0.0 0.0 0.0 0.00633 0.33355 Uiso Fe Si 0.0 0.0 0.0 0.00633 0.33355 Uiso Si This rule seems tricky if one wants to make an unit cell consisting of sites occupied by multiple atoms like A2-type Heusler alloys. Actually, I came up with an idea to place a “transparent” dummy atom using Nsc option at the top of the atomic position list to bypass the rule, and it seems to work. But I’m not sure this is the best way. Does anyone have other or better ideas? Thanks in advance. Kotaro ////====// Kotaro SAITO High Energy Accelerator Research Organization Institute of Materials Structure Science 1-1 Oho, Tsukuba, Ibaraki, 305-0801, Japan ////// ++ Please do NOT attach files to the whole list Send commands to eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/ ++
Re: Making an unit cell with all sites occupied by multiple atoms in FullProf
e. Is it correct? If correct, I’m curious about the reason why FullProf uses two different occupancy values for intensity calculation and cif output. Best, Kotaro ////// Kotaro SAITO High Energy Accelerator Research Organization Institute of Materials Structure Science 1-1 Oho, Tsukuba, Ibaraki, 305-0801, Japan ////// > 2016/10/03 20:00、Leopoldo Suescun のメール： > > Dear Kotaro, > If you keep a physically sensible structure, any trick is valid when trying > to deal with software limitations. > If you don´t have a site with full occupation or just two atoms in such a > site to put first in your atoms list then you will need to apply your trick, > as far as I know, to have a correct cif output. Unless you keep that in mind > and correct your output by hand when you finish your refinement. > Best luck, > Leo > > > 2016-10-03 5:41 GMT-03:00 Kotaro SAITO : > Dear FullProf users, > > I would like to make a pcr file for a Heusler alloy with so-called A2 > structure, in which three atoms are completely disordered. > (See Fig.1 in http://dx.doi.org/10.1088/0022-3727/48/16/164011 > or this direct link > http://cdn.iopscience.com/images/0022-3727/48/16/164011/Full/jphysd500490f01_online.jpg) > > For example, a straightforward description of A2 Heusler alloy Co2FeSi would > be like this. > I m -3 m <--Space group symbol > !Atom Typ XYZ Biso Occ In Fin N_t Spc > /Codes > Co Co 0.0 0.0 0.0 0.5 0.01041 0 0 00 > 0.00 0.00 0.00 0.00 0.00 > Fe FE 0.0 0.0 0.0 0.5 0.00521 0 0 00 > 0.00 0.00 0.00 0.00 0.00 > Si SI 0.0 0.0 0.0 0.5 0.00521 0 0 0> 0 > 0.00 0.00 0.00 0.00 0.00 > (general multiplicity = 96, multiplicity of (0,0,0) is 2, so Occ=0.02083 when > fully occupied by one atom) > > But, as many of you know, FullProf assumes that "THE FIRST GIVEN SITE IS > FULLY OCCUPIED OR THE FIRST AND SECOND ATOMS ARE IN THE SAME SITE WITH TOTAL > FULL OCCUPATION (If this is not the case, change the order of atoms to obtain > correct values for the content of the unit cell)” (quoted from a output file). > Accordingly, a cif file generated after running of a pcr with the atomic > position above shows unintended values as below. > loop_ > _atom_site_label > _atom_site_fract_x > _atom_site_fract_y > _atom_site_fract_z > _atom_site_U_iso_or_equiv > _atom_site_occupancy > _atom_site_adp_type # Not in version 2.0.1 > _atom_site_type_symbol > > Co 0.0 0.0 0.0 0.00633 0.66645 Uiso Co > Fe 0.0 0.0 0.0 0.00633 0.33355 Uiso Fe > Si 0.0 0.0 0.0 0.00633 0.33355 Uiso Si > This rule seems tricky if one wants to make an unit cell consisting of sites > occupied by multiple atoms like A2-type Heusler alloys. > > Actually, I came up with an idea to place a “transparent” dummy atom using > Nsc option at the top of the atomic position list to bypass the rule, and it > seems to work. > But I’m not sure this is the best way. Does anyone have other or better ideas? > Thanks in advance. > > Kotaro > > ////// > Kotaro SAITO > High Energy Accelerator Research Organization > Institute of Materials Structure Science > 1-1 Oho, Tsukuba, Ibaraki, 305-0801, Japan > ////// > > > ++ > Please do NOT attach files to the whole list > Send commands to eg: HELP as the subject with no body text > The Rietveld_L list archive is on > http://www.mail-archive.com/rietveld_l@ill.fr/ > ++ > > > > > > -- > Dr. Leopoldo Suescun > Prof. Agr (Assoc. Prof.) de Física Tel: (+598) 29290705/29249859 > Cryssmat-Lab./Cátedra de Fisica/DETEMA Fax: (+598) 29241906* > Facultad de Quimica, Universidad de la Republica. Montevideo, Uruguay > > Ahora la cristalografía importa más (www.iucr.org) Crystallography Matters > more. ++ Please do NOT attach files to the whole list Send commands to eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/ ++
