Metal ion source with surface melting by application of an electric field.

摘要

Experiments show that by applying an electric field to a metallic surface it is possible to melt the last layer of atoms of a metal surface. This is based in the fact that the electric field is screenedby the superficial layer of the metal and has no effect on the surface subrayers. We have therefore the parameters electric field and temperature. Our data show that it is possible to melt the surface of tugnsten with a temperature of around one third of the bulk melting temperature, when an electric field of approximately 15 V/nm is applied to the surface. In this way it is possible to build up small protrusions in the surface that emit a coherent beam of ions of 10<5> ions/s from a single atom and focussed to 3<o>, coherent. These beams may allow to write metallic lines of atomic dimension on a substrate. Also it can be obtained the coherent emission of an electron beam of high brightness useful for electron microscopes of high resolution.