I was reading about carbon family where it was mentioned that electrical conductivity of graphite increases with temperature while thermal conductivity decreases.

However, I could not find a suitable explanation for that. According to me, electrical conductivity should decrease with rise in temperature as it happens in case of conductors.

Any help will be appreciated.

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    $\begingroup$ Graphite is not a typical conductor. In a way, it is related to semiconductors. $\endgroup$ Nov 6, 2019 at 6:28
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    $\begingroup$ It is a very non-linear effect. The conductivity increases in a certain range but above 100 °C it starts to decrease. I don't think there is any rock solid explanation. See link.springer.com/article/10.1007/BF01135029 $\endgroup$
    – AChem
    Nov 6, 2019 at 6:29
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    $\begingroup$ The mechanisms of heat and electrical conduction are different. Heat conductivity is encouraged by collective motions (phonons) that may become increasingly incoherent at high T. Electrical conductivity is harder to explain. Presumably pi electron delocalization is important, but why this should show a significant T dependence is not clear to me. A quick search suggests conductivity goes through a maximum with increasing T. Can you produce some references or specific temperature intervals? $\endgroup$
    – Buck Thorn
    Nov 6, 2019 at 10:32
  • $\begingroup$ My book does not mention any intervals.However ,from the above answers I understood that it depends upon the temperature intervals we are talking about. $\endgroup$ Nov 6, 2019 at 10:52
  • $\begingroup$ I don't understand your heat conductivity explanation(I don't know quantum mechanics ).Can you simplify ? $\endgroup$ Nov 6, 2019 at 10:55


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