Physics Library, Room 223A, Physics Building
The MU Physics & Astronomy Department’s Condensed Matter - Biological Physics - Electrical & Computer Engineering seminar series present Dr. Wolfgang Kreuzpaintner, Technical University Munich, "Development of In situ Thin Film Growth for Polarized Neutron Reflectometry," Wednesday, September 12, 4:00 p.m. in Room 223A, Physics Building Library.
Dr. Kreuzpaintner writes, "Thin magnetic films and heterostructures thereof are the basic building blocks of a large number of electronic devices whose fabrication is based on physical vapor deposition techniques. The sample structure, stoichiometry, and defect population are defined by and evolve with the deposition process and their precise control and optimization are of great importance. It is, hence, highly desirable to directly analyze the development of the physical properties of magnetic heterostructures, e.g. the magnetization, during the growth process and to correlate them with the structural parameters of the sample. While, the in situ characterization of thin films by electron- and photon-based probes as well as by scanning probe techniques is common practice, the in situ measurement of the magnetic properties of thin films using (polarized) neutron reflectometry ((P)NR) is an extremely challenging task. The collaborative effort between TUM, University Augsburg and MPI Stuttgart in constructing a mobile sputtering facility for the growth and in situ monitoring of magnetic multilayers, which can be installed at suitable neutron beamlines, will be presented: In particular, the current state in development will be shown, ranging from unpolarized and polarized proof of principle neutron reflectivity measurements on Ni/Cr and Fe thin films carried out at the ToF reflectometer REFSANS at the FRM II neutron source to the latest fast in situ PNR measurements at the AMOR beamline at PSI. For the latter, the “Selene” neutron optical concept, based on elliptic neutron mirrors is essential. An overview over the latest developments and future modifications as well as the completion work carried out to allow the setup to be applied for even broader scientific research will conclude the talk."
Refreshments will be served beginning at 3:30 p.m.