Hello
I got XRD data of Al-LLZO
I wanted to calculate its density, so I needed to know
how many atoms are in an unit cell but I couldn't find out
is there any way can I find it form this data? or if you know another way
please let me know
thanks
Hi.
you can't tell directly from a powdered diffraction analysis. From XRD it is possible to verify that this is really a cubic phase with a structure corresponding to La3Li7Zr2O12, with space group of Ia-3d. Dopant is not important right now. In the cif file of this compound (COD ID 7206766) it is stated that the number of formula units in the unit cell is 8 (is referred to as Z and no. of atoms is 8*formula). If the doped material is isotypal, just include it in the mole mass calculation, calculate the cell volume from the XRD and update the density.
Den(Calc) =[Molecular Weight]*[Z])/([Volume]*0.60225)
volume is in Angstr.^3, mol. weight is in g/mol, calculated density is in g/cm^3
No it will not be possible...and you xrd is appearing with more than one phase...hence different crystal structures....different unit cells....nd number varies....if it is pure single crystal nd you recognize phase then cell is identified so from literature one can get information...or from TEM verifies the results
Hello Heyongmin Yu , when you load a structure from databases or a CIF file, HighScore, for your convenience, also calculates the Density and other typical values from that structure data. You find these values when you select the Phase of interest in the Refinement Control tab.
Then in the Phase Object Inspector under the node "Derived data" you find all these calculated values. The Density oi indeed calculated as pointed out by Dalibor Matýsek.
Yes, I just wanted to show how to do it and that it's easy. Topas automatically calculates. the density of all phases included in the model too. Just because a sample is a mixture doesn't mean anything. The density can be calculated for each component separately if we know their chemistry and crystal structure. Another question is what to use such results for.
Please refer below links of the given entitled article to get some relevant feedback. Kindly note that the article is not peer reviewed yet.
Qualitative Analyses of Thin Film-Based Materials Validating New Structures of Atoms. (2021), https://www.researchgate.net/publication/352830671or http://dx.doi.org/10.13140/RG.2.2.27720.65287
I do not think so. However, you can find the detail of crystallinity, non-crystallinity, porosity, texture and noise factors along with overall characteristics of peaks. Again, you can find flatness or surface roughness of film by increasing/decreasing the film’s thickness. You can also find some other detail of your material from the X-ray reflection (XRR) data. You may refer to the article given at link; (https://www.researchgate.net/publication/352830671 or http://dx.doi.org/10.13140/RG.2.2.27720.65287). However, this article is in non-peer reviewed form.
Heyongmin Yu, you simply sum all the Wyckoff, that is the total number of atoms in the unit cell as in your attached picture, or after Rietveld refinement, select the structure under the Refinement Control in the List Pane then go to Object Inspector and look for Derived Data tree for the X-ray Density also the formula.
To have the better understanding about atomic structure, this is good if you first study the preprint article at link https://doi.org/10.21203/rs.3.rs-88120/v2
- Badges
- Science method
- Similar topics
- Methodology
- Crystallography
- X-ray Diffraction