Questions related to XRD Analysis
Why is it that after annealing, while the size of the particles has become smaller and the crystallinity has decreased with XRD, and the electrical conductivity has decreased, but the band gap has also decreased? Is such a thing possible or is there an error in the experiments and calculations?
I know that profex, Mercury and MAUD can all fit powder XRD data to structual data given by an CIF file for example.
However, I can't find a free software where I can fit only the peaks along a given direction, for instance only along . Whenever I load my CIF file into the software it shows all possible XRD peaks you would get when you do powder diffraction, this I can obviously not fit with my thin film data.
Thank you and have a nice day,
I prepared CdS and I got sharp peaks with high intensity in the XRD pattern. The peaks at 2𝜃 do not correspond to ICSD of the XRD patterns of cubic and hexagonal CdS nanocrystals. How can I discuss that?
Hi, I work on natural polymers i.e. gums polysaccharides. the pure materials are normally amorphous , i did a modification on a base material and its xrd showed an improvement and showed a broad peak. i reported that and got a reply from a reviewer that " add JCPDS number and crystalline size" Previously in our field people report in such a way I have also added references and up to my best knowledge I know that: " JCPDS record does not exist for them moreover for poorly semi-crystalline or amorphous materials you can't calculate crystalline size it will be useless to use " scherrer equation " .
Now how to politely reply to reviewer's comment?
My process is reducing IrCl4 hydrate using NaBH4 in excess and adding Au NPs. What should be the expectation in peak shifting, should it shift from left or right. Current XRD data shows that shifting to the right occurs with explanation that the Ir particles attaches to the surface of the AuNP resulting in compression. However, from some of what I've read, it should be shifting to the left due to their differences in ionic radii and lattice expansion. Any insight or literature recommendation to help me clarify the concepts will be greatly appreciated!
I am presently looking for any facility or institution to carry out one or more of these analyses for my research in Nigeria: X-ray diffraction analysis, Particle size analysis and thermogravimetric analysis. If you have these in your institution and/or are willing to collaborate on my research kindly reply.
P.S: My research falls under Material Science, Civil Engineering and Architecture
In XRD analysis I am having 2 different FWHMs, one is the original data FWHM value(0.096), and after refinement, I am having different FWHMs(0.38), which I can take for crystallite size calculation. Kindly help me thank you in advance
I made hydroxyapatite from mussel shells and ammonium phosphate and calcinated it after.
The diffractogram is given below and the crystallinity is calculated as follows
CI value is given by:
CI = (a(112) + b(300) + c(202))/h(211)
Using the relative intensities of the planes I202 = 24%, I300 = 58%, I112 = 57% and I211 = 100%, the calculated CI for the under-studied sample is equal to 1.39.
Could you explain why my crystallinity value is really low: 1.39%
At what crystallinity percentage should I consider hydroxyapatite of good quality for biomedical application or scaffolding?
I synthesized the nanocomposite of GO@SiO2
The XRD result shows multiple peaks at a low intensity ranging from 10.2 to 28.
What do these peaks indicate and why this has happened? Any ideas?
Honestly grateful if you shed some light on this issue.
I tried to bind urea with my hydroxyapatite, but XRD does not confirm it (peaks for urea was not found in the urea-HAp ) nanohybrid.
I tried to sonicate the HAP dispersion using a bath type, should I use a probe-type sonicator in dispersing the Hap instead?
Or should I adjust the urea-Hap loading of my sample?
Or was the urea solution not saturated enough before adding Hap?
The methodology is as follows:
Urea-HA nanohybrids will be synthesized following (Kottegoda et at., 2011) using a wet chemical method.
- Obtain an amount of (25 g) synthesized HA nanoparticles as described above and dispersed them in distilled water (100 ml) under ultrasonic mixing (30 kHz for 1 hour or 45 mins).
- Stir the resulting HA nanoparticle dispersion in a saturated urea solution (100 ml) or 150 g urea in 100 mL distilled water at 25°C for 12 h.
Scale up: 25g:150g = 1:6 urea to Hap loading
Scale down: 5 g: 30 g =1:6 urea to Hap loading
- Wash the product thrice with distilled water to remove excess urea, and dry at 50°C for 7 h.
- Then place the synthesized Urea-hydroxyapatite nanohybrid in a Petri dish or air-tight container.
Is micro-strain (ε= β/4tan θ) and Dislocation Density (δ=1/D^2) applicable to natural fiber urea formaldehyde composites as well as inoc,nano and metallic materials? if yes, then can anyone share research paper on it's my findings of those parameters are δ=3.708807 and ε=4.384302.
In some articles, the oxygen cage surrounding the rare-earth ion in orthoferrites like La3+ in LaFeO3 is described as dodecahedral, whereas in others, it is described as cuboctahedral. Which definition is more precise? then why?
Based on orthoferrites' distorted structure, the first nearest Oxygen ions to La3+ are 8 O2- ions, and the second nearest are 4 O2- ions. Can we, therefore, refer to the oxygen skeleton surrounding La3+ as a hexahedron while neglecting the second neighbors?
Because the Gd3+ ion in GdFeO3 is defined as an 8-coordinated ion.
I did a XRD analyses, and I wanna see it using X-Pert highscore plus. My x-axis was from 20-90 (2theta) when I was testing it, but the software is showing me from 5 to 75. The shape of the analyse is correct. But the range of 2theta is not correct. Can anyone help me with how to edit the x-axis?
In xrd test I got two values like Intensity and two theta ....I calculated in scarrer equation & attached some file...Please anyone can help me and also recalculated the nanoparticle size in Nanometer...
I have older version of x'pert highscore software and what to do for pdf2, pdf 4? Please suggest me or share the link of x'pert highscore software latest version (free)/ free pdf2, pdf4.
I am taking XRD samples at various pressures. I want to compare my sample with established literature.
I know you can download .cif files and view them at different energies using VESTA or mercury, but is there a way to do this at different pressures?
I have a problem with crystallite size in Topas refinement. I'm using the LVol_FWHM_CS_G_L macro and the problem I'm constantly facing is that the Gaussian contribution goes to a large number (infinite crystallite size), while the Lorentzian contribution gives at least a reasonable value.
LVol_FWHM_CS_G_L(1, 5.50322798`, 0.89, 7.68859526`, csgc, 2356.57349`_LIMIT_MIN_0.3, cslc, 8.63459021`)
And this is obviously simultaneous with wrong strain value in e0_from_Strain macro where both values G and L of strain approach the min limit.
I'm dealing with highly disordered alumina materials if you'd like to know that.
Thank you in advance!
In my case: LiBH4 - LiBr in different molar ratio.
I have the observed patterns (measured by XRD technique) for this mixture of compounds but I don't have .cif file or any reference to compare the calculated patterns.
I have already done Rietveld Refinement for individual compounds, i.e. LiBH4, LiBr
during calculation microstrain of doped and undoped ZnO. i found negative microstrain. for example = -0.22938 for 1% al doping , -0.27 for 2% Al doping.
- For instrumental broadening correction, we use caglioti formula which relates FWHM and diffraction angle (2theta).
- How can the same instrumental broadening correction be introduced when I am using integral breadth instead of FWHM?
I have an alumina sample in powdered form, and I'm trying to characterize it (the only information I have is that it's alumina). The XRD pattern of this sample is attached.
Below are some of the things that I've noticed but have trouble understanding:
- Is the slope between 0 - 10 degrees normal? If not, how should I solve this issue? For my other crystalline samples I've never observed something like this.
- The peak intensity is less than 200, which seems quite low to me. The background noise also seems quite signficant, but there are still some identifiable peaks between 30 - 70 degrees. I'm therefore having doubt about whether this a good quality XRD pattern that I can use, or is this a bad quality/invalid result?
- Also, is there a possibility for this to be amorphous alumina?
Any help is greatly appreciated, thanks in advance.
I am frustrated by Fullprof. I aim to refine structural parameters by Reitveld method using Fullprof and have watched dozens of tutorials on youtube. However, either I get an error related to intensity of the xrd data or i get a refinement with chi^2 equal to zero which ofcourse is not possible. Would appreciate some suggestions
I'm working on ZnO-doped rare-earth ions (RE) and for a given concentration we observe a 2theta shift toward lower values in the XRD results. XRD analysis shows that the vertical lattice parameter c increases while we record a decrease in the lattice parameter a.
If we attribute this shift to the substitution process of RE into the ZnO matrix, why we did not obtain an expansion in both lattice parameters?
Note that this shift is observed for all the peaks and we work with RE ions that present an ionic radius greater than that of the Zn2+.
If there are some references for help, I would be very thankful.
Is it possible to have different relative peak intensities in the xrd patterns of a sample taken with two different instruments and consequently with two different operators?And how is it possible?
Shouldn't the relative intensity be independent of the instrument conditions?
Thanks in advance for your helps
Hello dear researchers
I want to make a rietveld refinement for a new material (doped material) using fullprof.
The problem is that I need the cif file, but it's a new material that doesn't have a cif file. Can I use the cif file of the undoped material at the beginning of the refinement and then use the cif file generated by fullprof to finish the refinement?
Please, if you have any ideas, help me!
If you also have tips on how to do the rietveld refinement better, feel free to mention them.
My group start some research on the development of new biodegradable nanoparticles based zinc. We where intersted to observe that based powder X-ray diffraction analysis, it was almost no differences between the Zn oxide and the Zn hydroxide.
What is key to differentiate between both following your experiences based powder X-ray diffraction analysis!
I was trying to do the quantitative calculation of crystal size by GSAS. I looked for the standard calibration alumina is really really expensive. My lab has some well-oriented alumina (0001). Its peak is very very sharp. Can I use it to do the calibration and work out the instrument parameter? Or is there any other cheaper alternatives?
I synthesized ZIF-93 by the method of aqueous phase in the article, but unlike the article, I synthesized a tetrahedral structure instead of rhombic dodecahedron. zif-93 is composed of zinc acetate dihydrate and 4-methyl-5-imidazolecarboxaldehyde. Can you tell me what causes the formation of tetrahedra?
I am using GSAS 2 to analyze images and integrate intensity v. 2theta plots. Is there a way I fit a background and subtract it inside GSAS 2? I typically just import it into Origin Pro and do it that way, but I would really prefer to do it in GSAS 2 natively.
I have an XRD pattern of valleriite. This mineral consist of brucite (P-3m1) and nukundamite (R-3m) layers. The layers are not "fit" perfectly, so the pattern repeats after ~21 brucite unit cells or 17 nukundamite unit cells in layer ("a" lattice constant). I have constructed this structure in VESTA combining 2 different phases. But the supercell seems too big for a direct Rietveld refinement in TOPAS.
I can refine my XRD using brucite-like and nukundamite-like phases separately, but reflections (0 0 l) are less intensive than it should be.
Are there any possibility to take into account the (0 0 l) reflections in TOPAS or refine less complicated and big hybrid structure with shift between brucite and nukundamite layers? Or is there any software what can refine this kind of structures?
Thank you for your answers.
Mesoporous silica was loaded with o-cresolpthalein indicator in a single step using CTAB and TEOS, Can somebody help me with its xrd analysis how do i interpret it? i did it at 2-90 degree and its showing a peak at 2 degree what does that show? shape or its elemental analysis?
I have done the Single crystal XRD analysis from which i got cif file. but i need morphology structure for my compound from WINXMORP software. so kindly explain how to use and get the structure.
I found maximum publications related to the electron distribution are done by the maximum-entropy method (MEM) through Rietan-FP software. But the Rietveld refinement using FullProf is also able to do the electron density mapping through GFourier technique.
Hence, I would like to know, if someone calculates electron density mapping from GFourier (FullProf.), then will it be acceptable for publication in a good journal? If so, please share some published articles related to the electron density mapping from GFourier/FullProf for references.
Hope you will share your valuable thoughts & discussion. Thank you all in advance.
Through my read some of the papers, I find that the welding efficiency may reach 100%, so the separation of the metal occurs away from the welding area (during the tensile test).
From your point of view: How do you evaluate the microstructure of welding zone?
I am confused about miller indices... Generally, I have observed that miller indices are represented by (hkl) for cubic or hexagonal structures. However, these represent 3D structures like (111) and others.
But for graphene, I have seen different XRD graphs which show a peak at (002). If graphene has a 2D structure, why do we have to treat graphene as a 3D structure according to the present plane through miller indices?
Hello dear all,
I'm considering the relation between crystallite size and BET-specific surface area for nanoparticles. We know that the specific surface area increases with decreasing crystallite size (smaller crystallite size - higher SSA). Why might exceptional circumstances (smaller crystallite size - lower SSA) arise?
Thank you in advance.
Hello friends, recently I saw GSAS II can do Rietveld refinement and it's free. I wanted to ask, can it do phase quantification to tell how much of each phase is in the XRD data? Can it load multiple CIF files to do refinement? is there also other free, open-source software out there that can do these functions?
Hello friends, I have attempted multiple times trying to get structure factor values from a CIF file. I tried to use Vesta, but I saw some researchers mentioned it to be not accurate. I try to use Mercury from CCDC, but not sure if it can output structure factor data. Do you guys know if the Mercury software can output structure factor data, or any another software is able to?
Greetings all scientist!!
I would like to know, which is the best software for Rietveld refinement among FullProf vs Rietan FP.
Thank you all for Your wonderful opinions in advance.
I am doing research on natural fiber composites. For composite analysis the tests are as following
Is that possible a sample can be use in more than one test?
Please help me
I want to know whether it is possible to do or understand the Molecular dynamics or Nucleation dynamics from XRD data/result by Rietveld refinement or by any techniques from xrd.
Thank you very much for your suggestions or answer in advance.
I use this program for Rietveld Refinement. My operational system is the latest Ubuntu. I'm just getting the output of the refinement directly in my terminal.
Appreciate any help.
I have XRD pattern for silver nanoparticle. But there is no peak values on XRD pattern. How can I find out the peak values? Kindly suggest.
I recently measured XRD of intermediate temperature prepared gamma-alumina and of course got 3 typical peaks (311), (400) and (440) on the pattern (d-spacing by XRD peaks is correct).
However, the positions of the rings in the SAED image seem not to match this XRD pattern. For example, the common d-spacing of (311) is around 0.239 nm (2.39 Ang.) whereas the most closed number of the ring is around 0.225 nm. The numbers of the other two peaks are also slightly lower than common figures.
Or SAED ring of (311) is not obvious, so instead of (311), this ring (0.225 nm) could possibly be (222)? But in this case, peak (222) on XRD is not that obvious.
Is this possible? I wonder if the machine I used has been well-calibrated?
Can anyone recommend software for single crystal film XRD data fitting to extract parameters like lattice constant, film thickness, etc.?
Actually I have prepared Al-VPO. But I did not get any peak of Al in the XRD pattern of Al-VPO. So it might be well dispersed or amorphous? If so then which is the active sites if I'll use it for any oxidation reaction?
synchrotron xrd- data ranges from 0 to 20 degrees(exact theta value) where as x-ray-XRD data ranges from 0 to 80 degrees(exact 2theta value)
I am working on a research project and I needed to quantify my XRD results. I had planned to do reitveld refinement using the Xpert highscore software. I have PDF2 has my reference card, but unfortunately all my selected candidates don't have structural information in PDF2. I am hoping that PDF4 which is the updated version, might have the structural information needed for my candidates.
If anyone here has access to PDF4, will it possible for them to check whether 4-5 reference cards have the necessary information? I will be extremely grateful and will help me in speeding up my research project