Prof. Martin McCoustra BSc, PhD, DSc, CChem, FRSC, CPhys, FInstP, FRAS

• EPS Representative on University International Development Committee
• EPS Representative on University Validation Panel for the Study Group International Study Centre
• EPS Teaching Coordination Committee Member
• EPS Undergraduate Strategy Committee Chair
• EPS Outreach Group Member for Chemistry
• EPS Marketing Group Member for Chemistry
• Chemistry Teaching Laboratory Group Chair
• Chemistry Outreach Coordinator

Surface Science

Surface science borders on chemistry, physics and engineering; and even strays into life and environmental sciences. Surface science underpins nanotechnology and its application. The methodologies in the surface science toolbox have broad application. Our research activities illustrates that breadth with activities stretching from understanding fundamental aspects of the chemical evolution of the Universe to developing new ambient environment methods for modifying and analysing surfaces.

1. Laboratory Astrochemistry of Surfaces and Solids

The Universe is molecular in nature. Molecules play a crucial role in controlling the evolution of the Universe but where do those molecules come from? In the last decade or so astronomers and astrophysicists have realised that surface and solid state chemistry is absolutely essential if the chemical diversity of the Universe is to be fully explained. Our work focuses on understanding the thermal, photochemical and radiation-induced processes that might be operating in astrophysical environments.

Figure 1. The Eagle Nebula, a dense active star-forming region of the Milky Way where surface and solid state processes are crucial to understanding the evolution of a rich chemical complexity.

2. Plasma-Surface Interactions: Surface Analysis and Modification

Ambient atmospheric plasmas are a complex environment offering unique opportunities. Our interest in such plasmas stems from developing a novel surface analytical technique known as PADI-MS (plasma assisted desorption/ionisation mass spectrometry). Our research focuses on understanding the processes underlying PADI-MS with the goal of improving its analytical utility in applications involving the analysis and modification of soft, organic surfaces.

Figure 2. Illustrating the practical simplicity of PADI-MS! A plasma pencil irradiates a pharmaceutical tablet in front of a mass spectrometer inlet. It might look hot, but the blue “flame” in this image is safe to the touch.

3. Energy Dissipation and Redistribution at Metal Surfaces

Molecules colliding with metal surfaces can undergo significant energy redistribution; energy can flow from translation to rovibrational degrees of freedom. Energy in molecular rotational and vibrational motion close to a metal surface can be dissipated by non-adiabatic processes involving the metal conduction band electrons. We have investigated the former using molecular beams and state-resolved laser spectroscopy and are developing reaction nanodiode methods to allow us to investigate the latter.

Figure 3. Schematic diagrams of device structures for reaction nanodiodes suitable for investigating non-adiabaticity in surface reactions on carbon material surfaces. Upper device has a metal-semiconductor (Schottky) structure while the lower device has a metal-insulator-metal structure.

1. 'Highly Efficient Electron-stimulated Desorption of Benzene from Amorphous Solid Water Ice', J.D. Thrower, M. P. Collings, F. J. M. Rutten and M. R. S. McCoustra, Chem. Phys. Lett., 2011, 505, 106-111.
2. 'Photon- and Electron-stimulated Desorption from Laboratory Models of Interstellar Ice Grains', J. D. Thrower, A. G. M. Abdulgalil, M. P. Collings, and M. R. S. McCoustra, D. J. Burke, W. A. Brown, A. Dawes, P. J. Holtom, P. Kendall, N. J. Mason, F. Jamme, H. J. Fraser and F. J. M. Rutten, J. Vac. Sci. Technol. A, 2010, 28, 799-806.
3. 'Thermal desorption of C₆H₆ from surfaces of astrophysical relevance', J. D. Thrower, M. P. Collings, F. J. M. Rutten and M. R. S. McCoustra, J. Chem. Phys., 2009, 131, 244711.
4. 'Applying Laboratory Thermal Desorption Data in an Interstellar Context: Sublimation of Methanol Thin Films', S. D. Green, A. S. Bolina, R. Chen, M. P. Collings, W. A. Brown and M. R. S. McCoustra, Mon. Not. Roy. Astron. Soc., 2009, 398, 357-367.
5. 'Laboratory Investigations of the Interaction between Benzene and Bare Silicate Grain Surfaces', J. D. Thrower, M. P. Collings, F. J. M. Rutten and M. R. S. McCoustra, Mon. Not. Roy. Astron. Soc., 2009, 394, 1510-1518.