Anomalously Isotropic Electron Transport and Weak Electron-Phonon Interactions in Hexagonal Noble Metals

The electrical transport properties of typical hexagonal metals are anisotropic because of their anisotropic lattice structures. Unexpectedly, we show that the electron transport properties in hexagonal close-packed (hcp) noble metals are almost isotropic. Although the electron transport properties of an individual electronic band are highly anisotropic, the total contributions are almost equal in different crystalline orientations because of the complementary contributions of different bands. The electron transport is severely limited by phonons for metals with multisheet Fermi surfaces and optical phonon polarizations. However, it is found the electron-phonon interactions are weak in hcp noble metals, although their Fermi surfaces and phonon spectra are complicated. The electronic structure acts as a phonon filter, resulting in small electron-phonon scattering rates. The weak electron-phonon interactions are beneficial to electron and thermal transport, indicating hcp noble metals have great potential to be used in electronics and solar cells.

Automated summary

The electrical transport properties of hexagonal close-packed noble metals are almost isotropic due to the complementary contributions of different bands. These metals have weak electron-phonon interactions, resulting in small electron-phonon scattering rates, which is beneficial for electron and thermal transport. This suggests that hexagonal close-packed noble metals have great potential in electronics and solar cells.