Hello,
I guess Structure refinement is the best way. From XRD data, maybe the precision on oxygen position is not high (even if probably reasonably good). In this case, choose neutron data.
Other theoretical methods include :
1. bond valence calculations. It consists in determining the position that would affect less the "standard" oxidation state of oxygen. probably a very rough indication of what u could be.
2. energy minimisation. from classical interatomic potential potential, you can have a quite precise idea of what is the equilibrium position of oxygen in a given spinel structure.
3. DFT calculations. better but not simple.
Refinement would be the best solution( even if from XRD), energy minimisaiton can be quite efficient too.
Guilhem
Respected Guilhem
Thanks for giving this answer. Yes you are quite right but neutron diffraction is not available everywhere, mostly people solve it by XRD, although not precise. Just tell me which parameters we have to put for DFT calculations in Wein2K. Please send me the link of any past paper in which cation distribution of spinel structure has been solved by DFT calculations using Wien2K program. I have a code but new user and in learning process.
Thanks with Good Energy!
If you do not know DFT, it would be more easy to start with energy minimisaiton with classical potentials.
using GULP for instance: for this, google "gale" and "gulp" and oyu will find it.
Respected Guilhem
Thanks with a lot of information about DFT software.
Dear Researchers
I want to ask about cation distribution in ferrites from xrd analysis. Mostly in the research papers, people applied three approaches, one is Fruhashi, second is Bertaut and third one is R-factor. In Bertaut method, after finding the intensities ratio which is sensitive for cation distribution, mostly the authors write the concentrations of cations in A and B sites but how???? Rietveld analysis is clear, integrated intensity formula is clear and then intensity ratio is clear but how the concentration values???? Please help???
Hello
I guess this was explained in original Bertaut'spapers.
Nevretheless, if you know a bit a Rietveld code, you can simulate different configurations and thus simulate the corresponding XRD diagrams. By changing the occupancy oin each site, you can extract the Relationship between integrated intensities ratios and site occupancy.
Quite simple.
Hoping it helps
please see through the research articles
http://aip.scitation.org/doi/pdf/10.1063/1.4946663
http://iopscience.iop.org/article/10.1088/1742-6596/755/1/012050/pdf
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