Dear Respected RG Experts
How the valence state of transition metal ions present in spinel ferrites can be accurately determined qualitatively and quantitatively?
Is it valid to assume a valence state of a particular cation by just looking its chemical formula and structural analysis like XRD, FTIR etc?
As the important properties of this class of materials are strongly dependent on the cations (their valence state) and their distribution at A and B sites, is it sufficient to explain their properties without a precise knowledge of their valence states?
What are the techniques and methodology adopted in general or specifically?
Is there any gap between these assumption and actual experimental values? If yes, by how much and please highlight the significance of these actual experimental values in understanding their properties?
Please provide relevant articles/ sources.
Thank you
You can use XPS and/or EELS spectroscopy to determine valence state of metals and FTIR spectroscopy in characteristic for oxides region: 800-100 cm^-1 to determine changes in cations distribution.
Thank you Dr Adrian for the answer and suggestions.
With best regards
Dear Professor Elangbam Chitra Devi ,
We usually use XPS to know the oxidation states of the elements in their compounds or composites. Moreover, I agree with what Professor Adrian Radoń mentioned.
Best regards,
Thank you Dr Mostafa for the answer and comment.
With best regards
if you have structural data (obtained by diffraction) you can use the bond valence sum method. in particular you have to calculate the bond lengths using your structural data and then use these values to obtain the valence. here you can find a brief explanation of the method:
https://www.iucr.org/resources/data/datasets/bond-valence-parameters
if you want to read something more, look for papers of I.D. Brown
Thank you so much Dr Alberto for the information and the valuable suggestions.
With best regards
Chitra
Hello Elangbam,
you can use XPS to determine the oxidation state and Mossbauer spectroscopy or XRD rietveld refinement to identify the sites position.
Thank you Dr. Thalles for the answers.
Almost all the answers here are similar. But, actually I am looking for the relationship between any of these two methods and a combination of cation distribution and valance state studies used for explanation of its properties say, magnetic, electric etc. As it is important to know both the valence state and distribution of cations, say magnetic moment depends on both parameters. To my limited knowledge, mostly they are studied independently (not simultaneously) and explained the properties (specially cation distribution is studied without exact knowledge of valence state). That is, it seems that both are necessary but one is always found missing.
With best regards
Thank you so much Dr. Artur Sir for sharing the possible routes for determining the valence state of an element.
With best regards
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