Does the bond between atoms affect Thermal Expansion?

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Homework Statement

From a journal I read that the cobalt-based perovskite cathode usually has better ionic and electrical conduction but higher TEC compare to Maganite-based perovskite cathode. Because of the Co-O bond is weaker than Mn-O bond.

e.g.
Cobalt-based perovskite cathode, La_0.3Sr_0.7CoO_3-x has thermal expansion coefficient(TEC) at around 20x10^-6K^-1 while La_0.65Sr_0.3MnO_3-x with TEC around 10 x10^-6K^-1
...probably this is not a very good comparison because the La to Sr ratio is a little bit different...

The Attempt at a Solution

Is it because of the weaker bond of Co-O bond, the mobility of Oxygen ion increase thus better ionic conduction; And the Co-O make further distance because of weaker bonding force when heat is apply causing high TEC value.

...extra question...sorry can't change the thread tittle...
And i did read somewhere before about the peroskite structure, ABO3, where A is the larger atoms at 8 corner of the unit cell and B is the smaller cation at the center of the unit cell, and if A is much larger than B in radius, the gap in the unit cell is bigger so the oxygen ion can move through the gap easier. I found that Mn and Co is in same row in period table, just Co has 2 extra electron and proton compare to Mn so its size is smaller...probably not much smaller, but does this size difference affect the mobility of oxygen ion too?

 

[Greg Bernhardt]

I'm sorry you are not generating any responses at the moment. Is there any additional information you can share with us? Any new findings?