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Physical Society ColloquiumInterview for Faculty PositionElectronic Structure Investigations of Conventional and Nanostructured MaterialsMatthew HallsIndiana UniversityDue to the imminent failure of SiO2 as a gate oxide layer as semiconductor device feature sizes continue to decrease, there is a growing need for alternative high-k dielectric materials. Aluminium oxide (Al2O3), deposited by atomic layer deposition (ALD), is one of the most promising SiO2 replacement materials under current investigation. Theoretical results obtained using Si cluster models with appropriate boundary conditions to investigate the initial surface reactions of TMA and H2O with the 2x1 reconstructed hydrogen-terminated Si(100)surface are presented. The results of the different Si(100)-2x1 cluster models are very similar providing a consistent view of the reaction energetics and furnishing critical insight into recent experimental observations. Comparisons are made between cluster models for Si(100) and Si(111), elucidating differences in surface reactivity. The revolutionary physical properties and attractive structural characteristics of carbon nanotubes and related nanomaterials make them unique nanoscale environments in which to carry out chemical reactions, offering the potential for catalysis through `solid solvation' along with variable pore size to accommodate molecular guests. The effect of confinement inside nanostructures on chemical reactivity is illustrated using first-principles calculations carried out for archetypal reactions inside carbon nanotubes. The interplay between local medium effects and steric interactions give rise to guest-host effects reminiscent of those found for inorganic and biological systems such as zeolites and enzymes.
Thursday, February 12th 2004, 10:30
Ernest Rutherford Physics Building, R.E. Bell Conference Room (room 103) |