Aberration-Corrected Scanning Transmission Electron Microscope with atomic resolution spectroscopy under controlled environmental conditions: AC-eSTEM

Lead Research Organisation: University of York
Department Name: Physics

Abstract

Atomistic structural, electronic and chemical models are the basis of modern material science, with data acquired under regular high vacuum conditions by analysis of mainly static specimens. However, the properties and hence functionality of many materials crucially depend on the environmental conditions to which they are exposed. Accordingly, relevant analyses of structure, composition and properties need to be conducted under controlled continuous dynamic conditions and the vision of this project is to enable and fully integrate the capabilities needed to accomplish these goals to understand nanomaterial-environment interactions, and ultimately to create nanomaterials by design.

The overarching vision of this proposal is to fill the need for the fully integrated nanomaterials analysis with single atom sensitivity under dynamic process conditions in environmental conditions. The aim is to provide the state of the art tool available to UK research community to address the outstanding materials problems that underpin a number of EPSRC research themes from manufacturing the future to health and environment.

Fully in situ and operando operations are needed to ensure the integrity of sample data. In practice this extends from sample synthesis or activation, through the ensuing operations, reactions or other processes or tests.

Hence, resources are sought to establish a state-of-the-art, aberration corrected STEM instrument (200 to 40 kV) with 0.08 nm image resolution and comprehensive analytical functions for chemical and electronic state analysis with electron energy loss spectroscopy (EELS), related imaging filter (GIF), direct electron detection, and elemental analysis with a transformational high sensitivity (and acceptance angle) silicon drift detection (SDD) energy dispersive x-ray (EDX) spectrometer.

The new instrument will be modified at York to include added unique functionalities, along the lines of the research led by the group. Methods and some hardware will be transferred from the original proof-of-concept and aged (2005) first generation instrument at York. The advantages of the open aperture 'gas-in-microscope' concept promoted at York are expected to be especially significant at the lower accelerating voltages of 80 and 40 kV to be available to reduce damage due to specimen-electron beam interactions.

The new instrument and attendant expertise will be organised, actively promoted, operated and managed as a new national capability with connections to the national SuperSTEM and ePSIC laboratories, including CI representation from both organisations, for advice and user guidance and active assistance external promotion and strategic as well as tactical management. Wide networking will add to the framework for organising the new capability but will not exclude more ad hoc bilateral interactions; in part to promote the core science needed at the heart of such an 'organisation'.

The scientific benefits of the proposed centre for excellence in environmental aberration corrected STEM will greatly contribute to the current research initiatives in the UK related to nanomaterials for energy applications, information technologies/internet of things, and catalysis. The key contribution will be in fundamental understanding of the nanomaterials environment interactions enables trough atomistic imaging and analysis of the dynamic processes that take place either during material fabrication or in action.
The project will make a significant contribution to what the future of the UK and of the world will look like; through better understanding of societal, scientific, economic, and environmental challenges and opportunities.

Planned Impact

Pathways to create and capture the full impact of the development at York are a major goal of this proposal through delivering a widely accessible and properly supported national capability for environmental STEM, with training, workshop and outreach activities.
This will support transformational change in key applications of nanomaterials. As a Tier 2 national access facility, the benefits will include access to the latest analytical methods in AC-eSTEM and integrated advances in detectors and spectroscopy, complemented with broad expertise in advanced electron microscopy.
The proposed state-of-the-art facility with national access will underpin EPSRC major research themes, including 'manufacturing the future' & 'nanoscale design of functional materials', for diverse materials and device applications, including in Catalysis, Materials for Energy and IT. The impact strategy will be advised by external advisory board.

The scientific impact of this proposal will come from the diversity and importance of novel materials and applications for improving current and future technologies. Initial focus will be on:
i) Energy materials developments for cleaner and more sustainable energy sources: novel alloys to withstand harsher environments of high T, stress, corrosion, etc. are essential for next generation nuclear power plants; materials hetero-structure control on the atomic level and atomic structural ordering are key for photovoltaics, thermoelectrics and spintronics.
ii) current applications in heterogeneous solid state-gas reaction catalysis; where improvement of the design of current and future catalysts will have tremendous economic and environmental benefits. Major contributions will be made by better management of the nano-structures and through fundamental understanding of solid/surface gas reactions at every step of catalyst production and operation, i.e. synthesis, activation, operation, degradation, and recovery/reprocessing.

Networking and collaboration are important to maximise the impact of the proposed tool and the research that it will enable. The potential for collaborations spans academia, industry and instrument manufacturers. We will generate bridges between communities that aim to solve common problems by different routes, e.g. the holder and high vacuum routes.

The outputs of the projects will be disseminated through scientific publications, workshops and outreach to the wider community. The Research and Enterprise Office at the University of York will assist with legal and IP matters, for commercialisation of the research development in collaboration with industry.

The acceleration of the impact of the new instrument will be a central component of the Centre for Energy Efficient Materials at York (CEEM) funded under the EPSRC Impact Acceleration Institutional Funding scheme. Collaborations within the networks of the national EM facilities SuperSTEM/ePSIC will provide access to simultaneous complementary tools required for solution of challenging materials problems. The close links to industrial partners and academic inter-institutional network will be fully exploited (knowledge transfer, student/researchers industrial secondment, workshops, etc) to accelerate the impact of this proposal.

Finally, this proposal will develop a cohort of the next generation of researchers and advanced electron microscopists, working on the new 'state-of-the-art' instrument and training in the latest microscopy methods. Delivery of the impact of this project will be based on our strong collaborations with academia and industry in creating new knowledge to improve industrial materials science, the economy and environment.

Publications

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