ProfessorCatherine Stampfl

Project Opportunities

Title: Quantum transport in molecule/carbon-based nanostructures for new molecular electronic devices

Summary of opportunity:

Various projects available in the field molecular electronics and sensors. Large scale ab initio calculations will be used to investigate and predict novel structures and systems. An example is described below.

Opportunity synopsis:

Metal porphyrins, metal phthalocyanines, and other related organic metal complexes constitute a class of versatile molecules that play an important role in diverse branches of science, such as biochemistry and materials science. For example, they have been considered as light absorbers in solar cells, and porphyrin molecules perched between electrodes made of metal clusters or graphene have been suggested in the context of molecular electronics. In the present project, the adsorption of such organic metal complexes on pristine and defected graphene and the consequent conductivity and physical properties will be investigated by means of density functional theory and quantum transport calculations. For discovery of new structures for molecular electronic applications, focus will be on the stability, electronic and magnetic properties and spin dependence of conduction.

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Project Opportunities

Title: Mechanism and control of diamond and graphene-based nanostructures using direct electric-field and laser excitation

Summary of opportunity:

To investigate the sculpting of carbon-based structures through controlled electric field and/or laser excitation, through first-principles based calculations.

Opportunity synopsis:

Nanotechnology is currently one of the leading scientific fields, intrinsically multidisciplinary and holding the potential to lead to real-world breakthroughs in for example the areas of nanoelectronics, clean energy, and green sustainable environment. Diamond and, graphene-based structures are of high current interest due to their unique physical properties and the ability to control and modify their atomic geometry and consequently their physical and chemical properties. This project will investigate how and whether the performance of several such carbon-based structures (surfaces, sheets and quantum dots) can be enhanced and controlled by using an electric-field and/or laser excitation.  For example selective graphene oxide reduction (removing C atoms) and  the stabilising of unique morphologies on diamond surfaces  through laser irradiation.  The studies will be carried out using first-principles quantum mechanical density-functional theory calculations and involve collaboration with Macquarie University.

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Project Opportunities

Title: Customising the acidity of novel nano-catalysts for desired catalytic reactions

Summary of opportunity:

To investigate through first principles calculations, the fundamental physics and chemistry of novel solid acid nano-catalysts with the overall goal of understanding and predicting their structure and reactivity.   

Opportunity synopsis:

Improvement in the sustainability and productivity of the chemical industry is urgently required to meet the increasing demand for fuels and chemicals and the impending depletion of fossil-based resources. Presently, solid acid catalysts play an increasingly important role not only in production of transportation fuels and petrochemicals, but also in generating renewable fuels and chemicals from biomass. Silica-alumina-based catalysts are most commonly used, whereby varying the Si/Al ratio in zeolite synthesis, the acidity can be tuned. At present however, a detailed understanding of the atomic scale mechanisms responsible for this is lacking. This project will address key questions regarding the fundamental physics and chemistry of these novel solid acid nano-catalysts with the overall goal of understanding and predicting their structure and reactivity.   The studies will be carried out using first-principles quantum mechanical density-functional theory calculations on supercomputer facilities.

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Project Opportunities

Title: Nano-catalysts for carbon neutral futures: Conversion of CO2 into valuable chemicals

Summary of opportunity:

To investigate functionalized porous nano-composites for advanced physical and chemical processes to convert CO2 to valuable chemicals from theory and computations.

Opportunity synopsis:

The project will investigate functionalized porous nano-composites for advanced physical and chemical processes to convert CO2 to valuable chemicals, which will dramatically enhance the environmental performance of industry and economic benefit of the greenhouse gas control. Advanced nano-catalysts will be explored  with state-of-the-art ab initio calculations, in synergy with experiments will be used to understand these nano-structures and their properties in depth. Such cutting-edge knowledge with process modelling and reaction engineering will have profound implications on designing combined CO2 capture/catalysis process to devise practical routes with reducing costs in a range of industrial applications.   Specific reactions of interest are the interaction of CO2 with methane to produce acetic acid, and syngas.

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Project Opportunities

Title: Understanding and design of new multiferroic materials

Summary of opportunity:

Using first-principle theory and calculation, this project will investigate puzzling complex phenomena in multiferroics with the aim of designing new multiferroic materials for the possibility of using them in novel applications.

Opportunity synopsis:

This project will investigate puzzling complex phenomena in multiferroics with the aim of designing new multiferroic materials for the possibility of using them in novel applications. Many compounds will be studied which will reveal the atomistic interactions that are responsible for the electrical polarization of rare-earth orthoferrites and orthochromites, as well as novel multiferroics via defect-engineering. Investigations of polarization switching in e.g. BiFeO3 thin films, which is crucial for designing memristors will also be carried out. Further, doped FeO3 structures will be studied to explore  materials having a negative index of refraction as well the possibility of giant energy storage density in compounds. A broad and deep knowledge of multiferroics and complex phenomena in bulk and nanomaterials will be gained, which has the potential to lead to the realization of devices with enhanced and/or new functionalities, and that will improve energy efficiency and storage.

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Project Opportunities

Title: 2D materials - effect of strain on chemical reactivity; and the physics of borophene

Summary of opportunity:

Two projects: (i) To study the catalytic properties of 2D structures for the Oxygen Reduction Reaction (ORR) and determine how the catalytic properties are influenced by applying strain. (ii)  Investigation on the structural stability of pristine borophene, adhesive properties of multilayer borophene, and potential catalytic and transport properties

Opportunity synopsis:

Two-dimensional heterostructures have attracted a lot of interest for their unique physical and chemical properties. Among these properties, scientists have identified that these systems can function as catalysts for a large number of chemical reactions. The recent Nature Nano Review paper (Nature Nano 11, 218, 2016) co-authored by Novosolev (the graphene Nobel Laureate) shows the importance of this topic and its potential for the development of the field of catalysis. The purpose of this project is to study the catalytic properties of a 2D structure (to be agreed by the student and the supervisors) for the Oxygen Reduction Reaction (ORR) and how the catalytic properties are influenced by applying strain. This project should be implemented in either VASP or SIESTA. In another project, the 2D material borophene, which is a single layer of boron atoms, will be studied. This material has recently been prepared and reported by Mannix et al. (Science 350, 6267 (2015)). The purpose of this project is to perform a detailed DFT investigation on the structural stability of pristine borophene, adhesive properties of multilayer borophene, and potential catalytic and transport properties. The investigation should also incorporate the effect of external factors such as strain and an applied electric field.  

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Project Opportunities

Title: Modelling charge transfer in donor-acceptor molecule using TDDFT and Spintronics of main-metal organometallic chains

Summary of opportunity:

Two projects: (i) To identify the charge transfer mechanism in donor-bridge-acceptor molecules, whether superexchange or sequential hopping or a different mechanism, for the systems investigated (ii)  To explore the various spin-dependent transport properties of main-metal organometallic chains using nonequilibrium Green’s function theory and to identify those with interesting spintronic transport properties.  

Opportunity synopsis:

TDDFT has been applied for investigating the detailed mechanism of charge transfer in donor-bridge-acceptor molecules (for example, J. Chem. Phys. 137, 22A512 (2012)). The purpose of this project is to extend this approach for studying bridge mediated charge transfer in organic system(s) of interest for photovoltaic applications using the Octopus real-space real-time implementation of TDDFT using equilibrium geometries produced by either GAUSSIAN or SIESTA.  The objective of these simulations is to identify the charge transfer mechanism, whether superexchange or sequential hopping or a different mechanism, for the systems investigated.   In another project, main-metal organometallic chains will be studied. These structures have drawn a lot of attention in the chemistry due to their unique physical and chemical properties. The purpose of this project is to explore the various spin-dependent transport properties of these structures using nonequilibrium Green’s function theory as implemented in the Transiesta code. The atomic structures of the molecules and electrodes should be relaxed using the SIESTA code. The objective of these calculations is to identify main-metal organometallic chains with interesting spintronic transport properties.

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Project Opportunities

Title: From Defects to Devices: Designing atomic defects for quantum technologies

Summary of opportunity:

There are several projects available in this area. Point defects in semiconductors/insulators with specific properties are a promising material systems for single-photon sources, sensors and qubits for quantum technologies. In order to design and engineer such structures, a fundamental understanding of defect properties is essential including geometry, electronic and optical properties, as well as stability.

In this research, first-principles quantum mechanical (density functional theory based) calculations will be used to study and predict defect structures of high potential for applications in future technologies. In combination with on-the-fly machine-learning techniques, insight into defect mobility and dynamics at room and elevated temperatures will be obtained. The theoretical insights developed in the project aim to inform the design of atomic defects systems for tailored applications.

Co-supervisor: Oliver Conquest, Hongyang Ma. Email contact: Catherine.stampfl@sydney.edu.au

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Project Opportunities

Title: Making Green Ammonia from Water and Air: Nitrogen vacancy engineering for N2 dissociation

Summary of opportunity:

Grand Challenge: The Nano and Quantum worldOwing to ammonia's significant contribution as a fertilizer and building block for the synthesis of various pharmaceutical products, it is recognized as one of the chemical mainstays of the modern world. As a fuel, ammonia has an energy density by volume that is twice that of liquid hydrogen and it is easy to transport. The predominant method for ammonia production has huge fossil-energy consumption and significant greenhouse gas emission. The urgency of replacing fossil fuels and mitigating the global climatic change motivates the global effort for the development of a sustainable energy system; crucial to this effort is the interconversion of small molecules such as CO2 and N2. Co-supervisor: Oliver Conquest, Hongyang Ma Email contact: Catherine.stampfl@sydney.edu.au

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Project Opportunities

Title: Computational Quantum Mechanics and Artificial Intelligence: Designing 2D Heterostructures to Tomorrows Technology

Summary of opportunity:

Van der Waals heterostructures, formed by layering two-dimensional (2D) materials, are revolutionizing material science and technology due to their unique properties and the large number of crystals possible from 2D combinations.(1) The analysis of the electronic structure gives important information to understand fundamental properties of this novel class of materials, which is crucial for performance optimization of devices.(2,3)

This project leverages quantum mechanics and artificial intelligence to explore the extensive heterostructure space (millions of novel bilayers), focusing on calculating their functional properties.(4,5) Initially, density functional theory will compute the target property of a selected set of heterostructures. The resultant database will then use to build machine learning models that will efficiently and accurately estimate the target property across all heterostructures. This approach aims to significantly accelerate material screening, expanding the range of potential hybrid materials for the scientific community. The combination of quantum mechanics and machine learning presents an innovative pathway for discovery novel materials.

Co-Supervisor: Marco Fronzi Email contact: marco.fronzi@sydney.edu.au, catherine.stampfl@sydney.edu.au

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Project Opportunities

Title: Understanding magnetic excitations in a new class of perovskites oxides

Summary of Opportunity:

Neutron scattering can explore excitations of magnetic materials with the energy scale from μeV to eV. Neutron instruments in the large scale national facility ANSTO will be used to investigate the magnetic excitations of new novel perovskite systems. An example is described below.

Supervisors

Shinichiro Yano- staff page at ANSTO, link here

Professor Catherine Stampfl.

Research location: School of Physics

Program type: PhD

Synopsis

Unconventional superconductors, multiferroics, and frustrated magnets constitute a class of magnetic materials that play an important role in diverse branches of condensed matter physics. These systems embody the complex interplay of charge, spin, orbital, and lattice degrees of freedom. Understanding fundamental physical laws of these systems can provides a pathway toward the development of next-generation functional materials, such as quantum qubits, multifunctional memory devices, and environmentally sustainable solid-state refrigeration technologies.

The present project, the magnetic excitations in new series of perovskite oxides will be investigated by means of inelastic neutron scattering techniques. By accurately measuring and analyzing the magnetic excitations, new classes of interactions can be uncovered. Using density functional theory, accurate quantum mechanical calculations will also be performed to assist in the interpretation of the measured results. A deeper understanding of these interactions broadens the prospects for controlling physical properties of magnetic material through magnetic field, electric field, and other physical parameters.