Probing dynamics at interfaces: options for neutron and X-ray spectroscopy

Abstract

Inelastic neutron and X-ray scattering experiments on surfaces and interfaces are a challenging topic in modern physics. Particular interest arises regarding the surfaces and interfaces of soft matter and biological systems. We review both neutron and X-ray spectroscopic techniques with a view to their applicability to these samples. We discuss the different methods, namely neutron three-axis, backscattering and spin-echo spectroscopy as well as X-ray photon correlation spectroscopy (XPCS), in the context of planar lipid membrane models as an example. By a combination of the different methods, a large range in momentum and energy transfer is accessible.

Keywords:

• Inelastic scattering
• Lipid membranes
• Neutron spectroscopy
• X-ray spectroscopy

Acknowledgements

We thank Christoph Ollinger (Institut für Röntgenphysik, Göttingen) for help in sample preparation and for an enjoyable collaboration in some of the original studies, Giovanna Fragneto (ILL) for support and collaboration on related studies, Matthias Elender (ILL) for technical and engineering support and the ILL and the ESRF for allocation of beam time.