Abstract
This paper describes the manufacture and properties of fine scale (Ø 260 μm) and dense (>96 % theoretical density) fibres consisting of Magnéli (TinO2n-1) phases for sensing and energy storage applications. In order to understand their operational limits, the re-oxidation of the Magnéli phases in air was examined using thermo-gravimetric analysis at temperatures up to 900 °C under a variety of heating rates. The material was characterised before and after re-oxidation via X-ray diffraction and scanning electron microscopy. The re-oxidation of the Magnéli phases was observed to begin at 650 °C, and the kinetics of the process was studied using the iso-conversional method. The calculated activation energy was consistent with Jander's three-dimensional diffusion model, where oxidation is limited by diffusion of oxygen through a layer of the oxidised product. An activation energy of 0.71 eV was obtained from kinetic analysis of the thermogravimetry data, which is in agreement with previous work on electrical conduction of Magnéli phases using impedance spectroscopy.
Original language | English |
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Pages (from-to) | 7597-7603 |
Number of pages | 7 |
Journal | Journal of Materials Science |
Volume | 49 |
Issue number | 21 |
Early online date | 23 Jul 2014 |
DOIs | |
Publication status | Published - Nov 2014 |
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Chris Bowen
- Department of Mechanical Engineering - Professor
- Materials and Structures Centre (MAST)
- Centre for Sustainable and Circular Technologies (CSCT)
- Centre for Nanoscience and Nanotechnology
- EPSRC Centre for Doctoral Training in Statistical Applied Mathematics (SAMBa)
- Institute for Mathematical Innovation (IMI)
- Centre for Biosensors, Bioelectronics and Biodevices (C3Bio)
- Centre for Autonomous Robotics (CENTAUR)
- Faculty of Engineering and Design - Associate Dean (Research)
Person: Research & Teaching
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Tim Mays
- Department of Chemical Engineering - Professor
- Institute for Sustainable Energy and the Environment - Director
- Centre for Sustainable and Circular Technologies (CSCT) - Co-Director
- Water Innovation and Research Centre (WIRC)
- Institute for Policy Research (IPR)
- Centre for Advanced Separations Engineering (CASE)
- EPSRC Centre for Doctoral Training in Statistical Applied Mathematics (SAMBa)
Person: Research & Teaching