Goldschmidt tolerance factor is defined as t = (RA+ RX)/sqrt of 2 (RB+ RX) where RA is radius of cation A, RB is radius of cation B and RX is radius of anion. This tolerance factor is used to study different structures. For perovskites structures it must be between 0.8 and 1.0. If tolerance factor is less than 0.71 and greater than 1.0 then we will get non-perovskite structures. Now question arises, in which way, tolerance factor (t) can be controlled to get proper/desired perovskite structure?
If you the the literature of perovskites, it is found that in A-site ( normally alkaline earth or rare earth metals ) and in B-site ( generally transition metal ions ) and anion is usually oxygen atom. If we use above mentioned metals, most probably we will get tolerance factor in the range of perovskites. But if we are trying to use some other metals, may be tolerance factor is changed. However it can measured by using their Shannon Ionic radii from literature and insert in the formula of tolerance factor. In this we can control the tolerance factor of perovskites.
Dear Hasan,
Goldshmidt tolerance factor for perovskites is a physical property for the structure of the molecules of the material and so it can be varied by changing the construction of the molecules. I would like that you study the the paper:
Structure and properties of complex hydride perovskite materials which may give an answer to your question. To get the paper please follow the link: https://www.nature.com/articles/ncomms6706
Best wishes
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