Analyzing the Resistivity Size Effect of Ruthenium Nanowires*

This poster summarizes results from recent experiments designed to characterize changes in resistivity as single-crystalline Ru(0001) terminated sheets and nanowires are progressively scaled down in thickness and wire length, respectively. Sheet resistivities are shown to obey size-dependent trends described by a semiclassical model developed by Fuchs and Sondheimer to account for contributions arising from surface scattering relative to those resulting from phonon interactions within the bulk of the material. Notably, low-temperature sheet conductivity measured from our samples exceeds that of conventional polycrystalline copper as thickness decreases below ~50 nm, which we attribute to the removal of grain-boundary scattering contributions and an ability to controllably create terminations resulting in near-specular surface scattering within our single-crystalline Ru sheets. Lithographically patterning these sheets to create nanowires (Plasmonics Inc.) appears to leave the devices with large defect concentrations, which weakens trends otherwise suggestive of ballistic conduction in shorter wires at lower temperatures.