Arrhenius plot for conductivity.
Arrhenius equation (in the case σ is conductivity)
σ=σ0 exp(-E/RT)
lnσ=lnσ0 -(E/RT)
So, graph is written as lnσ (for Y axis) versus 1/T. I understand this.
But I am confused when I found in the literature that author use lnσT (for Y axis) versus 1/T.
Hello,
Only diffusion coefficient should follow an Arrhenius law (activated process).
From Nernst-Einstein relation (google it to find the demonstration), conductivity
is proportional to: D/T and thus only sigma.T should follow an arrhenius law.
Then log(sigma.T) is the correct representation if we deal with random diffusion.
hoping it helps.
G. Dezanneau
Thank you for your answer G.Dezanneau. It helps a lot. Will do a few readings about the nernst einstein relation.
Thank you again.
lnσ versus 1/T plot indicates the effect of temperature on the mobility(diffusivity) of charge carriers. It ignores the effect of A (i.e. frequency factor). However, lnσT versus 1/T plot also includes the effect of temperature on the frequency factor (which includes both defect formation and defect migration).
I agree with G.Dezanneau. But i have to note that ln кT is correct for ionic conductivity, and lnк - for electronic (semiconductor ) one as they have quite different mechanisms of carriers mobility. [email protected]
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