Abnormal thermal-field emission from the ZrO2 / W nanoheterostructure surface

The paper presents a study of field emission properties of a ZrO2/W nanoheterostructure formed by a thin (~10 nm) ZrO2 layer at the point W microcrystal surface. It is found that at ~2000 K electron emission in the nanoheterostructure material starts at low extracting (Laplace) field strengths (below ~50 V/mkm). It is shown that in the stationary mode of electron emission from the nanoheterostructure surface, the emission current density may reach abnormally high values (about ~10^8 A/cm^2). A phenomenological model of the revealed effect - abnormal thermal-field electron emission from the surface of the conductor (metal)-thin dielectric layer type heterostructures is offered.