Field emission energy distributions of electrons from tungsten tip emitters coated with diamond-like film prepared by ion-beam deposition

Abstract

The energy distributions of electrons emitted from the surfaces of diamond-like tip cathodes under an action of strong electric field (10 7 V/cm) are presented. The diamond-like coatings were prepared on very thin tungsten tips with the curvature radii not more than 1 μm by means of ion-beam deposition under ultrahigh vacuum conditions (10 −7 Torr). The structure of the carbon films on tungsten tips was investigated by means of field emission microscopy. Also, the results on temporal stability of the field emission current of the cathodes and Fowler–Nordheim plots have been obtained. The work function of the diamond-like surface was estimated to approximately 2 eV. On the basis of experimental results the model of tungsten field emission cathode with relatively thin diamond-like film explaining the field emission energy distributions was proposed.