Field emission from HfC or Ni films deposited on single tip Mo field emitters

Summary form only given, as follows. Field emission from Ni films and from HfC films deposited on single molybdenum field emitter tips made from polycrystalline wire have been investigated. I-V data and Fowler-Nordheim analysis show that the work function as well as the tip radius have changed in both cases. The emission turn on voltage was lower by as much a 69 percent for HfC films, but only 5 percent for Ni films. Initially, similar field emission current stability was obtained for both films, however after heating the substrate to 400/spl deg/C the stability increased for the HfC coated emitters. These tips were next exposed to the air. Emission turn on voltages for HfC films increased after air exposure but they were still lower than those observed for Ni dosed tips. Furthermore, emission stability was better for the HfC coated emitter substrate.