Nanoscale structures at interfaces formed by lipids and from polymer/surfactant mixtures - deeper understanding provided by large-scale facilities
24. Juni 14:30 - 15:30
- The deposition to form soft matter nano-scale structures at interfaces is a delicate balance...
A measurement of the antineutrino spectrum of the fission products of U238
01. Juli 14:30 - 15:30
- In the last years, antineutrinos from nuclear reactors helped todetermine the parameters in the...
Implementation of a Longitudinal NRSE option for RESEDA at FRM II
15. Juli 14:45 - 15:45
- Longitudinal NRSE (lNRSE) has the possibilities to extend the accesible dynamic range of both NSE...
Seminar: Diffusion and Point Defects in Solids – Experiments with Neutron and X-ray Reflectometry
Diffusion and point defects (vacancies and self-interstitials) play an important role for various phenomena in application relevant and fundamental solid state research. Typical examples are grain growth, mechanical deformation, stress relaxation, ion conductivity, sensor applications, doping of semiconductors and many more. The control of diffusion and reaction of point defects on the nanometer scale is the key for the development of nanoscale devices.
In the present talk, experiments will be discussed, which are based on isotope multilayers and neutron reflectometry [1,2]. They allow the characterization of diffusion processes on the (sub)nanometer scale. Examples of recent research activities are presented for elemental semiconductors (Si, Ge), nanocrystalline Fe films, and Li ion conductors.
In the second part of the talk, synchrotron based in-situ X-ray diffraction and reflectometry studies are presented to investigate the role of vacancies for the relaxation of residual stress in thin Pt films at low temperatures . The results indicate that compressive stress relaxation is due to the creation of vacancies at the free film surface.
 H. Schmidt et al., Phys. Rev. Lett. 96 (2006), 055901.
 H. Schmidt et al., Acta Mater. 56 (2008), 464.
 W. Gruber, H. Schmidt et al., Phys. Rev. Lett. 107 (2011), 265501.
- Physics HS3
- Garching, Garching, Deutschland
- Prof. Dr. H. Schmidt, Technische Universität Clausthal
- TUM/FRM II