Thermal conductivity electrons. In this case the mean velocity is the Fermi velocity which is temperature independent. The mean free path is determined by the impurities and the crystal imperfections which are temperature independent as well. So the only temperature-dependent quantity is the heat capacity "c", which, in this case, is proportional to "T". So with "k" a constant. For pure metals such as copper, silver, etc. "l" is large, so the thermal conductivity is high. At higher temperatures the mean free path is limited by the phonons, so the thermal conductivity tends to decrease with temperature. In alloys the density of
Interfacial thermal resistance of the spectrum, one of the highest thermal conductances "measured" is between aluminum and copper. At room temperature, the Al-Cu interface has a conductance of 4 GW m K. The high thermal conductance of the interface should not be unexpected given the high electrical conductivity of both materials. The superior thermal conductivity of Carbon nanotubes makes it an excellent candidate for making composite materials. But interfacial resistance impacts the effective thermal conductivity. This area is not well studied and only a few studies have been done to understand the basic mechanism of this resistance. Interfacial thermal resistance Interfacial thermal resistance,