Functional Nanomaterials

Carbon Nanotube for the Optical Sensing of DNA and DNA Sequence Variations
The ability to detect and study a single molecule represents the ultimate challenge for biosensors. Recent progress in the fabrication of nanostructured materials and devices, such as nanoparticles, silicon nanowires, metal nanowires and carbon nanotubes have opened new avenues for achieving the goal of single molecule detection. Because the carbon nanotubes such as single walled carbon nanotubes are only one molecular layer thick, every atom is at the surface. A consequence of every atom being on the surface is the adsorption of any molecule onto the surface of a nanotube will change the optical properties of carbon nanotubes which means nanotube optcal sensors are capable of extremely high sensitivity. The method we propose will explore the unique optical properties of carbon nanotubes for the immobiliSation of specific biomolecules (Yang, W. R.; Thordarson, P.; Gooding, J. J.; Ringer, S. P.; Braet, F., Carbon nanotubes for biological and biomedical applications. Nanotechnology 2007, 18, 412001). The alteration of the optical properties by biomolecular binding will allow the detection of these subtle processes. The aims of this research proposal are: i) to develop techniques for the non-covalent functionalisation of the sidewalls of single-walled carbon nanotubes (SWCNTs) based on DNA hybridisation and ii) to explore novel nanoscale biosensor based on the unique optical properties we will use near-field optical scanning microscopy (NSOM) to characterise these carbon-nanotube-DNA hybrids.
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Microscopic Origin of Ferromagnetism of Diluted Magnetic Semiconductors
High-quality diluted magnetic semiconductors (DMSs) are required to realize spintronics – the next generation electronics. DMSs above room temperature have been widely reported, but there are strong variations in the reported spintronic behaviours. In particular, the origin of ferromagnetism is not clear. Therefore, there is a major opportunity for the application of new, element- and position-specific analysis techniques for revealing the microscopic origin of ferromagnetism in DMSs. In this project, we will employ atom probe and other microscopic techniques to study the nanostructural effects in DMSs. The aims are to understand the microscopic origin of ferromagnetism in DMSs, and to direct the fabrication of high quality DMSs.
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Nanotube Nanothermometers – Synthesis, Characterisation and Application
This project aims to directly measure the catalyst temperature of proton exchange membrane (PEM) fuel cells with carbon nanotube nanothermometers. Through measuring the temperature distribution of the catalyst, we can study the catalytic reaction at a nanometre scale. The resulting information will provide us with key engineering insights for (i) designing new kinds of electrolytes for PEM fuel cell that are thermally stable and durable, and (ii) improving the efficiency of the catalyst. Importantly, this work will make nanothermometers a practical and scientifically important method for nanoscale temperature measurements, and provide fundamental information on the oxidation behaviour of gallium in confined environments.

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Collaborator: Prof. Yushan Yan, Dept. of Chemical and Environmental Engineering, University of California, Riverside, USA.

High-resolution In-situ Characterisation of the Vapour-deposition Growth, the Structures and the Plasmonic Properties of Metallic Nanostructures
The project aims to explore the nucleation and growth mechanism of vacuum vapour deposition by observing the development of metallic nanostructures in the transmission electron microscope at the atomic scale. The surface plasmon resonances of the individual metallic nanostructures also will be characterized by electron energy-loss spectroscopy. The resulting information will provide us with key scientific insights for nanomaterials design and manipulation and will advance our understanding of the origin of surface plasmon resonances and their true correlation with shape, size and structure of nanoparticles.
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Collaborator: Dr Mosong Mo, School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney.

Ferroelectric-Ferromagnetic Tunnel Junctions
The project, a collaboration between the University of Sydney, the University of New South Wales and the Research Center at Jülich (Germany), is focused on the development of complex metal oxide multilayers for ‘spin’ electronic devices. We seek to investigate the fundamental interaction between lattice polarization of a ferroelectric layer and electron spin of a ferromagnetic layer in ultra-thin (1-30 nm thick) single-crystalline multilayer thin films. Using constrained two-dimensional geometry and atomic level proximity, we will fabricate and analyse spin-polarised junctions for ferromagnetic electrodes.

The project will provide a new and exciting method to modulate the charge in spin-based electronic materials with striking properties. Fabricated thin-film junctions will be investigated on the atomic scale, using advanced electron microscopy, including energy loss spectroscopy. Theoretical analysis will also be used to fully characterise the cutting-edge spin-polarised junctions that we will create in this comprehensive project.
Investigators: Dr Nagy Valanoor (The University of New South Wales), Prof. Paul Munroe (EMU, The University of New South Wales), (ACMM, The University of Sydney), Dr Kohlstedt (Jülich, Germany).