Talk:Ballistic conduction

Latest comment: 4 years ago by Footlessmouse in topic Mean Free Path decreases with temperature

Mean Free Path decreases with temperature

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The sentence in question (third paragraph): The mean free path can be increased by reducing the number of impurities in a crystal or by raising its temperature.

By raising the temperature one creates more phonons, on which the electrons can scatter, thus reducing the mean free path. Therefore, unless other temperature dependent factors dominate, the sentence should read: The mean free path can be increased by reducing the number of impurities in a crystal or by lowering its temperature.

23485ß6739 (talk) 16:33, 11 December 2016 (UTC)Reply

@23485ß6739: This is only true in conductors. Drude theory of metals gives that mean free path and mean free time are both vary inversely as the square root of temperature. In statistical physics, fluid dynamics, the ideal gas law gives a mean free path that varies as temperature, though. So it depends on the medium. Footlessmouse (talk) 06:58, 19 August 2020 (UTC)Reply

Section "Isotopically enriched diamond"

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At this moment, there is a brief section "Isotopically enriched diamond" that reads: "Isotopically pure diamond can have a significantly higher thermal conductivity. See List_of_thermal_conductivities". The present article is about ballistic conduction of electrons wheres the thermal conductivity of diamond is not related to electrons, but to phonons. Therefore, I do not see why anything about isotopically enriched diamond should be mentioned here, and I suggest removing this section. MScheffler (talk) 17:22, 12 February 2018 (UTC)Reply