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Three-dimensional (3D) micro- and nanostructural characterization using scanning electron microscope (SEM) and electron-solid interaction simulations (ESIS) has attracted broad interest in various research fields. However, 3D SEM-ESIS still faces key challenges in characterizing and modelling complex microstructures. In this paper, a new grid-based simulation scheme is developed to enable ESIS of complex microstructures. In contrast to the widely used region-based approach, the scheme presented here uses a grid of points to represent the spatial distribution of sample compositions, which allows numerical investigation of the effect of various geometric features such as interfacial diffusion zones and complex pores in the samples. The simulation results suggest that the interfacial diffusion zone and porosity significantly influence the scattering signals. It is believed that the presented scheme acts as a useful interpretation tool in understanding a wide range of materials and paves the way to SEM-based 3D reconstruction., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Non-equilibrium molecular dynamics was used to simulate the dynamics of atoms at the atom probe surface and five objective functions were used to quantify errors. The results suggested that before ionization, thermal vibration and collision caused the atoms to displace up to 1Å and 25Å respectively. The average atom displacements were found to vary between 0.2 and 0.5Å. About 9 to 17% of the atoms were affected by collision. Due to the effects of collision and ion-ion repulsion, the back-calculated positions were on average 0.3-0.5Å different from the pre-ionized positions of the atoms when the number of ions generated per pulse was minimal. This difference could increase up to 8-10Å when 1.5ion/nm 2 were evaporated per pulse. On the basis of the results, surface ion density was considered an important factor that needed to be controlled to minimize error in the evaporation process., (Copyright © 2017. Published by Elsevier B.V.)