Electron transport properties inRuO2rutile

Abstract

First-principles electronic-structure calculations were used to determine the electron-transport properties of ${\mathrm{RuO}}_2$ in the rutile structure. Our calculations were performed within the local-density approximation employing soft-core ab initio pseudopotentials and a plane-wave basis. The two independent components of the tetragonal plasma-frequency tensor, ${\mathrm{\Omega }}_{\mathit{p},}$xx, and ${\mathrm{\Omega }}_{\mathit{p},}$zz, were found to be identical within the calculational errors. The calculated isotropy of the plasma-frequency tensor agrees with optical and transport measurements. Our theoretical value for the plasma frequency of 3.3 eV is within 5–10 % of the experimental value as determined from optical and resistivity measurements. We find that the experimental resistivity can be fit accurately to the standard Bloch-Grüneisen model with additional terms representing optical-mode coupling and electron-electron interactions. Previously used models did not conform to the correct Fermi-surface topology. Our ab initio results demonstrate that the transport properties of ${\mathrm{RuO}}_2$ exhibit ‘‘normal’’ behavior as described by the Boltzmann equation.