Investigation of size effects in the electrical resistivity of single electrochemically fabricated gold nanowires

Single gold nanowires with diameters ranging between 80 and 300 nm were fabricated by electrochemical deposition in single-pore membranes. The wires were contacted by means of a macroscopic planar electrode on each membrane side. The resistance-versus-diameter behavior was measured and is discussed considering finite-size effects, i.e., additional electron scattering both at the wire surface and at grain boundaries. Resistance-versus-temperature curves display characteristics like a bulk metal that shows a linear behavior down to about 70 K and finally approaches a limited value below 40–50 K with a residual resistivity ratio ρ300 K/ρ20 K≈2.5. The temperature-dependent resistivity data of wires with diameters larger than 200 nm fit well with the model of Mayadas and Shatzkes for grain-boundary scattering, thus confirming that surface scattering is negligible in this range.