Tungsten oxide W18O49 nanorods with diameters of 15−20 nm were grown on tungsten thin films exposed to ethene and nitrogen at 700 °C at atmospheric pressure. It was found that tungsten carbide formation enhances nucleation and growth of nanorods. Atmospheric pressure field emission measurements in air showed a turn-on field of 3.3 V/μm and stable and reproducible emission current density (28 mA/cm2). At low current densities (<20 mA/cm2), the field emission current follows the Fowler−Nordheim model; saturation effects were observed above 20 mA/cm2.
Agiral, A., & Gardeniers, J. G. E. (2008). Synthesis and atmospheric pressure field emission operation of W18O49 nanowires. Journal of physical chemistry C, 112(39), 15183-15189. https://doi.org/10.1021/jp802756y