Simulation of the electric field structure of a three-dimensional atom probe
This article employed the finite element method and multiphysics simulation to analyze the structure of a local electrode atom probe.The impact of various parameters,including inlet diameter(φ),thickness(w),opening angle(α),entrance length(h)of the local electrode,the radius of curvature(ρ)of the specimen,and the distance(z)between the local electrode and the needle-shaped specimen on the local electric field structure near the apex of a specimen,was investigated.The result indicated that a higher evaporation electric field strength was achieved at the apex of the specimen,and the influence of local electrode on ion trajectories was reduced when the ratio of distance(z)to inlet diameter(φ)satisfied z/φ≥1.Specifically,the thickness(w)and opening angle(α)of the local electrode had a minimal impact on the electric field at the apex of the specimen.In contrast,the increase of the entrance length(h)of the local electrode improved the electric field strength at the apex of the specimen.Moreover,the radius of curvature(ρ)of the specimen increased as atoms continued to evaporate from the specimen surface.The electric field(V)applied to the specimen was proportional to the radius of curvature(ρ)of the specimen to maintain the required electric field intensity.The higher intensity of electric field corresponded to the greater applied electric field(V).
atom probe tomographylocal electrodefinite element simulationelectric field structureion trajectory
万方数据
维普
