Modification of the tungsten carbide field emitter surface to localize the electron and ion emission

Using field emission microscopy, the shape modification of the tungsten carbide emitter simultaneously exposed to high electric fields and high temperatures is studied. It is shown that in this case the emitter shape changes observed on the emitter surface are the same as those observed in the pure metal emitters. The possibility to grow a single nanoprotrusion on the emitter surface which can emit charged particles with stability similar to that for the carbon material emitters is demonstrated. The values of the emission current, current density, emission angle, and reduced brightness are comparable to those for the carbon nanotube emitters, and the advantage of this single nanoprotrusion is its complete reproducibility and capability to emit not only electrons but also ions.