Effect of Crystal Orientation on Vacuum Breakdown Characteristics of Copper Nanoelectrode

Aiming at the influence of surface work function and internal atomic structure of nanoelectrodes with different crystal orientations on the theoretical mechanism of vacuum breakdown, the current electrodynamically-coupled molecular dynamics and particle simulation method (ED-MD-PIC) was used in this paper. The effect of crystal orientation on the vacuum breakdown characteristics of copper nanoelectrodes was studied by comparing the evolution of characteristic parameters of different crystal orientations ({100}, {110}, {111}). The emission current and the shielding effect of space charge on the local electric field at the tip of the nanoelectrode at the initial time of different crystal orientations increase with the decrease of the work function of the crystal surface of the material. The necking, sharpening and evaporation of atomic clusters of nanoelectrode tips with different crystal orientations lead to differences in field enhancement factor and internal heat transfer rate. The higher electric-thermal field is the main reason for the lower critical electric field and vacuum breakdown delay of Cu {111} electrode. The maximum difference of the critical electric field of vacuum breakdown of nano-electrode with different crystal orientations is less than 7%.