Low-temperature electronic transport properties of ruthenium thin films and nanowires

Abstract

The electronic transport properties of atomic-layer-deposited Ru thin films and nanowires were investigated in the temperature range between 0.1 and 30 K by means of magnetoresistance measurements. The nonlinear behavior of the longitudinal and Hall resistivities was used to extract information on carrier densities and mobilities. The analysis revealed that for thin films, holes exhibit lower mobility but have a much greater concentration than that of electrons, in contrast to bulk at room temperature where the electron and hole densities are expected to be equal, with holes having a larger mobility. For Ru nanowires, the saturation of magnetoresistance suggests a vanishing electron concentration possibly due to excess carrier concentration at the edge causing increased recombination supported by defects. For Ru thin films, weak antilocalization effects provided insight into phase coherence and spin-orbit scattering lengths, indicating that electron-phonon interactions are the dominant scattering mechanism.