Modeling of nanotips fabricated by local electron bombardment

Nanotips have attracted increasing interest in several aspects of nanotechnology, particularly in nanotip-based microscopy and nano-characterization. Therefore, fabricating nanotips with well-defined shapes and in a highly controlled process is vital for these applications. Here, we present some characterization analysis of nanotips fabricated by the recently developed local electron bombardment method. We highlight the importance of using spherical crystal models to reproduce the nanotip atomic structure as a way to estimate the nanotip size, rather than using the conventional ring counting method. The nanotip shape is modeled by building the crystal structure of the nanotip apex to estimate its size. Then, the overall nanotip shape is estimated by sequentially destructing the entire nanotip and utilizing finite element simulation tools to build the nanotip model. The simulation model is made in a way to generate the same threshold electric field, in the field ion microscope, before and after the nanotip destruction.