First-principles study on field evaporation of surface atoms from W(011) and Mo(011) surfaces

摘要

The simulations of field-evaporation processes for surface atoms on W(011) and Mo(011) surfaces are implemented using first-principles calculations based on the real-space finite-difference method. The threshold values of the external electric field for evaporation of the surface atoms, which are similar to6 V/Angstrom for tungsten and similar to5 V/Angstrom for molybdenum, are in agreement with the experimental results. While the threshold value of the electric field and the local-field enhancement around the evaporating atoms agree with those expected from the conclusion of the previous study using structureless jellium, the induced charge around the surface atom has a significant difference from that obtained by the jellium model. (C) 2005 Elsevier B.V. All rights reserved.