Chemical reactions and growth processes on surfaces depend on the diffusion and re-orientation of the adsorbate molecules. A fundamental understanding of the forces guiding surface motion is thus of utmost importance for the advancement of many fields of science and technology. To date, our understanding of the principles underlying surface dynamics remains extremely limited, due to the difficulties involved in measuring these processes experimentally. The helium-3 spin-echo (HeSE) technique is uniquely capable of probing such surface dynamical phenomena. The present thesis extends the field of application of HeSE from atomic and small molecular systems to more complex systems. Improvements to the supersonic helium beam source, a key component of the spectrometer, as well as a detailed investigation of a range of five-membered aromatic adsorbate species are presented. The thesis provides a comprehensive description of many aspects of the HeSE method - instrumentation, measurement and data analysis - and as such offers a valuable introduction for newcomers to the field.
Chemical reactions and growth processes on surfaces depend on the diffusion and re-orientation of the adsorbate molecules. A fundamental understanding of the forces guiding surface motion is thus of utmost importance for the advancement of many fields of science and technology. To date, our understanding of the principles underlying surface dynamics remains extremely limited, due to the difficulties involved in measuring these processes experimentally. The helium-3 spin-echo (HeSE) technique is uniquely capable of probing such surface dynamical phenomena. The present thesis extends the field of application of HeSE from atomic and small molecular systems to more complex systems. Improvements to the supersonic helium beam source, a key component of the spectrometer, as well as a detailed investigation of a range of five-membered aromatic adsorbate species are presented. The thesis provides a comprehensive description of many aspects of the HeSE method - instrumentation, measurement and data analysis - and as such offers a valuable introduction for newcomers to the field.
Nominated as an Outstanding Ph.D. thesis by the University of Cambridge, UK Provides a comprehensive introduction to the helium spin-echo technique for newcomers to the field Combines aspects of instrumentation, experimentation and simulation Reports on a detailed investigation into the dynamics of aromatic adsorbate species Includes supplementary material: sn.pub/extras
Barbara A. J. Lechner
Adsorbate Diffusion Cyclopentadienyl Molecule on Surface Five-Membered Aromatic Molecules Helium Atom Scattering Helium-3 Spin-Echo High-Intensity Supersonic Beam Source Molecular Dynamics Simulations Pyrrole Molecule on Surface Surface Dynamics Thiophe Molecule on Surface