Hello, thanks for this tutorial. On the off chance you are still answering questions about this, is FullProf capable of multiphase quantitatvie analysis? The software I used for my school has been taken away and replaced with a software that consistently overfits data to the point that it cannot be used and I am trying to learn Fullprof to complete my paper. Before, I used RIR analysis to analyze a multiphase sample with cifs I saved to my computer, but Fullprof is not able to read the space groups from this. When I put in some space groups manually, I am told the spacegroups I insert do not exist (even though I am taking them directly from the CIF files and they are identical to what is on something like COD). Do you have any advisement on how to get past this issue?
Thank you for the video. You have negative y-coordinate (atomic position) for Oxygen, you kept that value as it is throughout whole refinement. Why didn't you consider that one? Can we visualize the unit cell with your refined atomic position?
Your question is hypothetical. Kindly give the name of the different phases in your samples so that I can suggest how to go for refinement. If your cif file is not available first go for indexing and find the lattice parameters. Then see all the possible space groups of the examined material reported in literature. This may be temperature dependence data or pressure dependent data. Check the PE loop. That will also check whether the space group is centrosymmetic or not. I am taking a example here. BaTiO3 is a prototype ferroelectric. It has R3m, P4mm, Amm2 and pm-3m space group possibilities. What ever you dope or how you prepare the sample it will be in this space group only. The best fit is your space group. I hope this is helpful. I can not write a lot here so sorry for that.
I can solve this issue and successfully rietveld( BiFeO3) XRD.Now I am working on (SrBi4Ti4O15) but facing different error when I am running like,no reflection found,there is an error in your input file , please tell me about that issues
The thin film xrd backgrounds are very noisy. You can simulate a xrd graph to find the peak position. I will not recommend doing rietveld refinement for thin film xrds.
Hello! Sir i have tried every possible video on the youtube to refine my data, and the least value of chi 2 is still not less than 8. Can you please do my refinement?
Average apparent size cannot be calculated (no size broadening)! Possible reasons: (1) The broadening of reflections is resolution limited (2) No size parameter has been refined (3) The resolution function is not properly given this issue generation on doing in fullprof. Another thing is that after following your steps, my chi-square does not decrease to near 1. It stays 68. I tried refinig atomic positon but On doingit doesn't proceed how to resolve this issue?? Another issue I am getting with doing gsas , I face a issue no reflection in the pwdr limit i do not get. I this it becomes after refining which leads to unrelaistic histogram scale factor and zero off set. what are ur views can i get ur contact??
To make a IRF file you need to run a standard sample in the XRD diffractometer. You can take standard as LaB6. Run this sample in the machine and collect the information like two theta, fwhm, peak shape parameters. Check one of the example file in the FullProf and put your own data for LaB6 measurements. Enter the IRF file when you convert cif to PCR.
I have two quiries plz sir do reply 1) i dont have that third file which u were talking about . I have cif file and my xrd and copied the intensity and made a new dat. File. 1)I am getting cycle 1 and chi2 :558 . . How to proceed from here
This a crucial case. Do the indexing. It will suggest a structure and lattice parameters. Then run the data in expo to find probable space group. Next do a polarization measurements to understand the space group is centro symmetrical or non centosymmtrical. Compare your structure with similar compounds. At end see the fitting with lowest chi2 of the each space group.
Tell me the sample name. I hope you have not correctly put the atomic position. Download the cif and then import. Please mail me with the problems you are facing. Satya
If you want to dope a element at A site of B site of the BiFeO3, add the element in the atom information with the atomic positions of A site or B site depending upon the size of the atom/ Ion. foe example if i want to dope Lanthanum in BFO then i will use Bi atomic position of BFO for La. This procedure can be done if the lanthanum substitution dies not change the structure of BFO. You can use same R3c. But if the substitution of La changes structure, then you have to go for dual phase refinement. foe example, 15% of La doping drives the crystal symmetry to rhombohedral and Orthorhombic dual phase. So, I have attached 2 papers link for your reference. Please read, if you have any problem mail me. aip.scitation.org/doi/abs/10.1063/1.4916927?ver=pdfcov&journalCode=jap DOI:10.1088/2053-1591/abdd50. Enjoy. Regards Satya
Kindly check in PCR file what is the number below "job". If this is not zero make it zero. Alternative, you can name you data file and PCR file same name. Just check.
Hello sir, how are you telling that at 9.50 sec while you are running the fullprof software you mentioned that it doesn't converged or something...what does it mean and how you are telling that I mean under what basis?... Please reply
You can start minimum with 10. The choice of this number basically depends on the convergence of the profile fit. You will know it after 2 to 3 cycles of run.
The error in lattice parameter is only active when the refinement tick is active in the box. To see the error, first refine and then check in the output file or sum file.
@@physicsdoneright sir i need a help…i have created a separate data file that includes 2 theta min , max , intensity…but whenever we browse the xrd data file then its not showing in that folder…folder shows empty…i can not select any xrd data file..plz help me
@deepa mam u can also suggest something regarding this? sir i need a help…i have created a separate data file that includes 2 theta min , max , intensity…but whenever we browse the xrd data file then its not showing in that folder…folder shows empty…i can not select any xrd data file..plz help me
Thank you sir, Am trying to refine a synthesized sodium silicate crystal xrd pattern against a cod 2106900 reference phase in fullprof and am get warning!! The fractional coordinate in almost the H exceeds 1.2!. Please is there a way i can remedy the warning as the refinement won't converge. While having a high chi^2 value of 13.9
Thank you very much for this tutorial. Can we convert PCR file to CIF file? I have seen an option for that, but am not fully aware of the process. And what if we have multiple phases in the pattern, can we get multiple phase information in PCR file while doing peak search and keeping the numbers less than 20, which is recommended to create PCR file via FullProf?
Thank you for your questions. 1. Certainly, you can convert PCR to CIF from the output option menu. But that file format is not in the standard format as per COD or other databases. If you want to create the CIF file please see the formats of databases. 2. Yes you can do multiple phase refinement and you can get the percentage of each phase. Kindly see my video for the rietveld part ii which is basic for dual phase or multiple phase. I always recommend to create PCR files from CIF files. If you will edit other PCR files to create your own sample PCR then some of the hidden parameters will have non zero value inside and the pattern will not converge to low rp or two values. I am happy to answer your question.
Thank you so much for this tutorial, I have a problem with my refinement of YBCO, The refinement won't converge and I'm having a chi^2 value of 0.145E+04
Hi, do you also know if it runs on MacOS? I have tried but everything works except loading background file and running the fullprof which generated that red colored data and fitted profile. Strange, but do you have any idea how to solve it?
thank you for giving good information sir about me but we doped different materials like (NBT-BT-BFO ternary phase diagram) how to arrange the atom position, please explain me
Okay. I understood you question. NBT is R3c or Cm depending on Polling. BT is p4mm and BFO is R3c. So if you have ternary phase then you need a simultaneous 3 phase refinements. Yes that would interesting to see. Go to the phase in rietveld and add all 3 phases separately. Then refine.
Tell me your Rp, Rwp, Rexp values. Tell me your how your took data means step size and data scan rate and range. Check in the SUM file that model is satisfactory or not.
Peaks are not fitted well. If you have completed all the refinements then i guess that your data collection may be creating problems. All XRD data are not eligible to make rietveld refinements. You need to take step size 0.01 min, slow scan rate 1 degree per min and range 10 to 90. You can still report with chi2 with value 5 but R paramo must be below 6 at least.
What does it mean by converge? I did not get that. You repeated three times and finally told it is now converged. Can you please tell me how to know whether it is converged or not? Thank you for this insightful video.
It's written on the screen at the end of each run. When each run is conducted by changing a parameter and then parameter will reach its optimum value, it will show that convergence is reached.😊
@@physicsdoneright Thank your for your response. Still did not find the converge term in the screen. Sorry for that. Can you please send the screenshot by highlighting this? Thank you.
This is the same file that you saved under the name ‘data.data’. I observed that there was an error in saving it with the ‘.data’ extension instead of the correct ‘.dat’ extension.
Thank you so much sir, it was very helpful but I still have some doubt, can you please make a video on how to refine the data if there will be shifting of hkl peaks to right and to left with doping.
Dear Selvaraj, Kindly specify the exact compound and dopant that you are using. This is a general question. In the example video, the material was R3c space group BiFeO3 and its a perovskite. If I do a rare earth doping it will put chemical pressure at A site means Bi site. But substitution at Fe site do not introduce structure change. and the structure changes to R3c to dual phase R3c+Pnma. These are my papers for reference. 1. aip.scitation.org/doi/abs/10.1063/1.4916927 2. iopscience.iop.org/article/10.1088/2053-1591/abdd50/meta. Thus, please specify you sample and dopant so that I can suggest space group for you.
Hello Sir, Thanks for the video . I am trying to do reitveld refinement for my sample . But after doing all the steps when I start the refinement , I am getting an error like "error on intensity file, check your instrument parameter parameter". please kindly suggest me regading this.
This problem is due to step size or spacing issue. The input file format is wrong. Please check the steps as follows 1. Line 1: initial 2theta then space then step two theta then space final 2 theta. example: 20.00 0.02 79.88 (Note: Check your data. It may be up to 4 digit after decimal.) 2. Line 2: paste the intensity value Save in filename.dat
For me after running, the blue colour is showing as straight line only instead of xrd graph. Also cycle 1 chi 2 : 00 is mentioned please identify the problem?
Yes, I can understand your problem. This problem usually happens but I don't have a scientific suggestion for this. I copy the folder to some other place before running the fullprof.
The displayed value of Rp and Rwp and chi2 at the end of refinements will decide the experiment data has converged to theory or not. Always check SUM file generated at output.
Sir, even though the cycles for refinement is given 15, only 1 cycle is running for me. I have tried so many times. What might the problem. Could you please explain it.
Hello sir, can you explain how to do refinement for material whose CIF file is not available such as 6 elements how make the CIF file phase name and lattice parameter is know how to make the cif file plz help me how manual make Cif file
Thanks for asking. To create data for IRF file you need to take a data for LaB6 in your diffractometer where you have taken your sample data under examination. Then from the xrd data of LaB6, find 2theta, Lorentzian shape and Gaussian shape parameter. Then keep the data in the format shown in rietveld example file. And finally run in the software
Thank you sir for the video. However, even after following each step it's not running for my case. Everytime it's showing, job interrupted and pattern 1 not found.
I want do size and strain analysis for CeO2, will you tell how to prepare IRF files, if possible please send model file. After refinement, using winplotr, I have generated IRF_HG. IRF_Hl, and IRF_Hpv. Using these files I have plotted in Origin, is this procedure is ok or not.
You can take any file format described in the fullprof examples files. To make a IRF file you need to run a standard sample like LAB6 in the same Diffractometer where you have take that XRD data of the sample and replace the lorentzian and gaussian components in the IRF file format and run the sample in full prof. Or you can do the BREADTH package which is much advanced for size strain (i have another video uploaded for that)
See the literature report value of thermal factors of the particular elements for the compound. And fix the value. Do not refine it. The thermal factors should be a positive value because it is the displacement in angstrom square.
I keep doing the analysis as in your video and always getting "error on intensity file, check your instr parameter". Do you have any idea how to fix it? (My Ins = 0)
Please make sure you have prepared the intensity file in correct way. The intensity file must have intitial 2theta then space then step 2theta then space final 2theta. Then enter and paste all the intensity data. I hope your step size is not written properly. Note: First try to run the intensity file data in winploter, then run in full prof.
@@physicsdoneright it was a problem with .dat file indeed, thank you! Now I'm facing a problem with refinement - it is quite good (chi2=32), but one peak does not appear in it. (If I manually increase the scale it appears). I'll be grateful for any tips from you.
Yobs - Ycalc is a almost flat line (less than 200 points diff and major peak intensity is around 18000) yet Chi2 value is around 10, what can be the reason/reasons for this, Sir?
In theory xrd profiles are not broadened but due to crystallite size, strain and dislocation or due to experimental part, peak shapes broaden. So we need a instumental file that accounts for the broadening not resulted from the sample it's self. It's optional in fullprof. If you want to calculate crystallite size or strain from full prof, you may need that file. I can not write more here. Please see literature
Hlo sir, hope you are Fine. Sir, in atomic scale parameters my software did not refine it. It shows the conv is not reached... I tried so many times but it only shows conv is not reached kindly guide me what should I do now... If I have to change the parameters or any other process then tell me how can I do. Thanks and regards
Hi, I had the same issue and tried increasing the number of refinement cycles (iterations) to 30 and then 50. Convergence usually reached before 50 cycles in each case. I hope this helps. Best.
Thank you for the tutorial video.... It's very helpful for the seeker like us ... Also due to elaborative explanation regarding each parameters it is unique for the refinement procedure... Btw I have a question regarding IRF file ... How can I get the IRF file??? Is there any issue if I used the IRF file of LaB6, given in example file.... If possible can I get your email ID???
Hello, take a xrd data of LaB6 from the same diffractometer from which you have taken your samples data. It is a property of the instrument. You can't use the lab6 file available in the example file of the installed software.
You can start the refinements from 0.1 to the optimized refined value. You can also check previous refinements single crystal data of your samples. Note that B values not to be negative.
materialsproject.org/materials/mp-542920/. This is for LaFeO3 which is a pnma structure. You can you add one atom for Gd with same atomic position as La.
This method is a structural refinement process that means you need to have a reference model. If you don't know the phase try to find the space group from various structural determination software.
The TCH pseudo-Voigt profile function (Thompson, Cox and Hastings, J. Appl. Cryst. 20, 79 (1987)) is used to mimic the exact Voigt function and it includes the Finger‘s treatment of the axial divergence (L.W. Finger, J. Appl. Cryst. 31, 111 (1998)). I took it with an aim for crystallite size and strain calculations.
Estimated values of Figures of Merit: goodness of fit (χ2), profile residual (Rp), weighted profile residual (Rwp), expected weighted profile residual (Re) and background corrected reliability (R) factors (cRp, cRwp, cRe) where to get these values?
Dear Sir, I m doing all the steps according to you…but it shows the singular matrix errror… i need urgent of this…can i send u cif file and raw data file?
Dear, do not refine all the parameters at same time. If refining a parameter gives you singular Matrix then keep it fixed with its CIF file value. people often get singular Matrix dialogue box in u,v,w and occupancy refinement. Keep them fixed.
@@physicsdoneright Sir, I have a DAT file. So without using CIF file downloaded from COD, I directly browse my data file in the pattern section and I have entered the values of lattice parameter, B, X, Y, Z, Oct and angles in the refinement section. After saving this, I have tried to run fullprof. But it keeps showing some error..
@@lekshmi833 please make sure 1. U, V, W parameter 0.06, -0.05, 0.08 put its starting value, 2. Then make sure you have chosen the right peak profile and shape
I too had this problem. The problem was with my antivirus deleting some important files after scanning for the virus. If u have an antivirus, try refining once before scanning or add FullProf files to ignore list. Hope your issue will be resolved.
Hello sir.. thank you for the tutorial.. I am following the refinement process 10-12 runs, but still my chi2 value is 333 and the graphs r not converging. Is there any process to resolve it?
IRF is called an instrumental resolution file. You need to create that file. You need to take xrd data of Si or LaB6 in the same diffractometer where you have taken the xrd data of the sample to be refined. Kindly check my 2 videos in the playlist, how to create IRF files.
Hi Sir.. Please mention ur mail id. I didn't found that on ur profile. I need to learn this software... I am having issue while puting pcr file b4 refinement
Sir can u please help me in this regard..i tried watching this video but facing some problems to do it.. can u please provide email id to reach u... For my research it's urgent
Dear Dr. I followed all the steps but the lowest chi2 value I could get is 6.8. And I don't know how to proceed. Could you please help me? My material is cubic BaTiO3.
You can refine the following parameters such as anisotropic thermal factors, use of IRF file, different background files, peak asymetry. I note that if your rp, rwp, rexp are still less than 10, you can still report higher chi2 values even 5 or 6. If your data quality is very high means the data has been taken in very slow scan and step size 0.01, you may also get higher chi2. Poor data often gives low chi2.
