Dr Varghese Swamy

Dr Varghese Swamy is a Research Fellow in the Department of Materials Engineering at Monash and at the ARC Centre of Excellence, Design in Light Metals.

His research concentrates on exploring the fundamental behaviours of functional nanoscale materials. In particular, he is investigating phase transition behaviours under pressure and stress, crystal lattice changes resulting from size reduction, changes in the phonon spectra, and changes in mechanical properties – known as nanomechanical behaviours.

Most recently, his focus has been on nanostructured titanium dioxide (TiO₂) phases and nanoscale semiconductors - for example silicon. In his work, Dr Swamy uses synchrotron-based diffraction and spectroscopic methods.

Dr Swamy is passionate about his research in nanoscience and nanotechnology. “Such changes realised in nanostructured materials offer unprecedented avenues for tuning and designing properties outside the limited range offered by their bulk equivalents.”

He has discovered that the TiO₂ phases (nano-anatase and nano-rutile) provide potentially beneficial materials for use in the areas of energy and the environment. These include their use in photocatalysis, photovoltaics (especially, dye-sensitized solar cells), photochromics, electrochromics, and sensors. He is also exploring ways to synthesise high-coordinated nanoscale TiO₂ with the aim to improve its mechanical properties.

Dr Swamy has looked at nanomechanical behaviours and finite-scale phase transitions in semiconductor materials such as silicon and germanium. These have significant impact on their advanced applications in Micro-Electro-Mechanical Systems (MEMS), Nano-Electro-Mechanical systems (NEMS), MOSFET-type electronic devices* and biosensors, and on their characterisation.

The research which Dr Swamy is undertaking is particularly significant in advanced manufacturing. It is at the cutting edge of high-pressure materials research in nanoscience and nanotechnology, and advanced synchrotron-based experimentation. This could lead to the improved design and development of engineered semiconductors and energy materials.

He has established an international collaborative research programme which allows access to experts in synchrotron-based high-pressure experiments and advanced synthesis of nanostructured materials. These scientists are from the University of Bayreuth and Universität Duisburg-Essen in Germany and the Advanced Photon Source, Chicago in the US.

At Monash, Dr Swamy works closely with Professor Barry Muddle, the Professor of Materials Engineering.

In his wider interests Dr Swamy is exploring the computational modelling of materials using a range of methodologies which include first-principles quantum-mechanical calculations and computational thermodynamics.

* metal-oxide semiconductor field-effect transistor

Above: Cotunnite-structured ultrahard Titanium Oxide phase.

Selected Publications

Swamy V. (2008) Size-dependent modifications of the first-order Raman spectra of nanostructured rutile TiO₂. Physical Review B (in press).

Swamy V. &  Muddle B.C. (2007) Ultrastiff cubic TiO₂ identified via first-principles calculations.Physical Review Letters 98, 035502.

Swamy V., Menzies D., Muddle B.C., Kuznetsov A., Dubrovinsky L.S., Dai Q. & Dmitriev V. (2006) Nonlinear size dependence of anatase TiO₂ lattice parameters.Applied Physics Letters 88, 243103.

Swamy V., Kuznetsov A., Dubrovinsky L.S., McMillan P.F., Prakapenka V.B., Shen G. & Muddle B.C. (2006) Size-dependent pressure-induced amorphization in nanoscale TiO₂.Physical Review Letters 96,135702.