First Principles Calculation Of Lattice Thermal Conductivity Of Metals Considering Phonon-Phonon And Phonon-Electron Scattering

The effect of phonon-electron (p-e) scattering on lattice thermal conductivity is investigated for Cu, Ag, Au, Al, Pt, and Ni. We evaluate both phonon-phonon (p-p) and p-e scattering rates from first principles and calculate the lattice thermal conductivity (jL). It is found that p-e scattering plays an important role in determining the jL of Pt and Ni at room temperature, while it has negligible effect on the jL of Cu, Ag, Au, and Al. Specifically, the room temperature jLs of Cu, Ag, Au, and Al predicted from density-functional theory calculations with the local density approximation are 16.9, 5.2, 2.6, and 5.8W/m K, respectively, when only p-p scattering is considered, while it is almost unchanged when p-e scattering is also taken into account. However, the jL of Pt and Ni is reduced from 7.1 and 33.2W/m K to 5.8 and 23.2W/m K by p-e scattering. Even though Al has quite high electron-phonon coupling constant, a quantity that characterizes the rate of heat transfer from hot electrons to cold phonons in the two-temperature model, p-e scattering is not effective in reducing jL owing to the relatively low p-e scattering rates in Al. The difference in the strength of p-e scattering in different metals can be qualitatively understood by checking the amount of electron density of states that is overlapped with the Fermi window. Moreover, jL is found to be comparable to the electronic thermal conductivity in Ni. Published by AIP Publishing.