An abnormal thermal field emission point electron source

A study of the field emission properties of ZrO₂/W nanoheterostructures (NS) is presented. The NS was represented by a thin (~10 nm) ZrO₂ layer at the tip of a needle-shaped W<;100> and W<;111> microcrystals. It has been revealed that at temperatures NS substance within 1950K to 2150K the NS shows an abnormally high normalized brightness (up to ~ 10⁶ A/(cm² sr V)) and high stability of field emission properties. The revealed phenomenon of a sharp rise in emissive ability of the ZrO₂/W NS in a certain range of ZrO₂/W layer thicknesses and NS substance temperatures was called “abnormal thermal field emission” (ATFE). A phenomenological model of the physical mechanism of the ATFE from planar nanoheterostructured surfaces is offered.