Structural Evolution and Thermal Runaway of Refractory W and Mo Nanotips in the Vacuum Under High Electric Field from PIC-ED-MD Simulations

Abstract We performed multiscale-multiphysics simulations for W, Mo and Cu nanotips under high electric field to investigate their structural evolution thermal runaway process. The critical values the prebreakdown condition are predicted be 311 MV m −1 , 570 675 Cu, W respectively ( R 0 = 1 nm, H 100 nm). boiling point of metal is found a good predictor strength initiation runaway. For made refractory metals such as Mo, process determined by rapid growth small protrusions subsequent sharpening thinning stress on apex region. On other hand, more intense atomic evaporation caused ejection large droplets generated recrystallization necking molten region at nanotip. differences in observed evolutions between during event clearly show strong influence melting points nanoscale.