Abstract by Berg Dodson
Physics and Astronomy
Resistivity Evolution of the Alumina Diffusion Barrier in Catalytic Carbon Nanotube Growth
Alumina plays an integral part in forest growth of carbon nanotubes (CNTs) growth, acting as a support layer and a diffusion barrier for iron catalysis. Due to CNTs’ highly conductive nature, attempts have been made to incorporate them into electronic devices and circuits. The challenge with these circuits is that the current must flow through the resistive alumina, ρ = 1016 Ω m. However, these devices exhibit a resistance several orders of magnitude lower than would be expected based on alumina’s resistivity. Indeed, measurements of our CNT devices exhibited resistances of 350 Ω, compared to > 10 MΩ prior to CNT growth on the same device. I explore whether iron or carbon diffusion into the alumina is primarily responsible for this change through XEDS and electrical characterization. Results from these experiments show that both carbon and iron impact the resistivity of the alumina.