Modelling and characterisation of electron beam processed low dimensional nanomaterials

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Scientific context and collaborationHigh resolution transmission electron microscopy HRTEM has become a common tool for studying the structures of low dimensional nanomaterials, such as graphene or carbon nanotubes. Major challenges in advancing the current capabilities of TEM, beyond structural analysis on the atomic-scale, include 1 establishing TEM as the primary tool for the quantitative characterisation of material dynamic transformations; and 2 enabling novel synthetic routes for the controlled modification of low-dimensional materials using the electron beam e-beam as a direct processing tool. A paradigm shift for HRTEM and STEM is the controlled manipulation and positioning of individual atoms within a nanomaterial, termed "The Atomic Forge". The latest advances in HRTEM are paving the way for the control of materials with atomic precision, a process currently achievable only by scanning tunnelling microscopy STM, but with the inherent advantages of stability at room temperature and accessibility throughout the 3D volume of the material, free of the low temperature surface assembly limitations associated with STM Turning the dream of using the e- beam as the ultimate synthetic tool into a reality requires comprehensive understanding, both theoretically and experimentally, of material properties at the fundamental level, in terms of their dynamic behaviour and interaction under the processing e-beam. This PhD project will focus on the investigation of materials under e-beam irradiation, combining the insights of computational modelling and imaging with atomic scale resolution, to predict and explain the dynamic behaviour of low dimensional nanomaterials processed in the TEM. It will involve the close, iterative comparison of theoretical predictions Besley, Chemistry with experimental TEM observations Brown, Engineering. The project will take advantage of the extensive expertise, based in the Computational Nanoscience group, in the School of Chemistry, across a wide range of computational techniques, from modelling large scale systems approaching 500k atoms with classical potentials to high-level density functional theory calculations. The dynamic effects of the e-beam on structure transformations will be modelled explicitly using the group's in-house CompuTEM algorithm resulting in multislice image simulations for direct comparison with experimental TEM images with atomic resolution.