| Carbon nanotubes have been the subject of extensive research over the past few years. This is due to the unique properties of carbon nanotubes brought about by its electronic, mechanical and chemical properties. Low dimensional structures that were previously in the domain of theorists can now be tested experimentally with carbon nanotubes based devices. Nanostructured materials with exciting new properties are now predicted to bring about a whole new revolution to the world and the way we live. The main focus of this work is in the area of low temperature synthesised carbon nanotubes with the extreme limiting case of synthesis at room temperature. Whilst research groups worldwide are pursuing the holy grail of synthesising perfectly structured nanotubes, using either carbon electrode arc-discharge techniques or laser ablation or a less structured form at typically 700°C using chemical vapour deposition (CVD), this thesis explores the formation of carbon nanostructures at lower temperatures using CVD techniques. Besides the advantage of using a wider variety of supporting substrates, electrodes and its possible use in conducting polymer composites, the work will also contribute and add to the knowledge base of low temperature synthesis. This thesis is focused on the characterisation of nanotubes as this is critical in understanding the properties of nanotubes and allows for the fabrication of proof of concept devices in targeted applications. In this thesis, the synthesis of low temperature carbon nanostructures and nanotubes, and spherical carbon structures will be presented and discussed. Briefly, carbon nanostructures have been successfully synthesised at below 350°C and lower defect level carbon nanotubes have been synthesised below 400°C using a novel thermal barrier layer technique. Methodologies for exploiting the low temperature growth process for future applications are discussed. |
