Surface examination of ultra-sharp cold field-emission cathode

An experimental cold field-emission cathode, based on metal-oxide-insulator structure has been analyzed by several non-destructive evaluation methods in order to describe the material properties and electrical behaviour of the sample. Owing to the fact that the tip of the cathode reaches nanoscopic-scale, several different evaluation methods have been incorporated. Firstly, the scanning electron microscopy (SEM), along with the electron dispersive spectroscopy (EDS) was performed to describe general proportions of the shape and the abundance of elements present in the surface layer. Secondly, the scanning low-energy electron microscopy (SLEEM) was applied in order to visualize the crystalline microstructure of the cathode surface. Finally, the epoxy coating covering the cathode tip was characterised using the dielectric relaxation spectroscopy (DRS) method