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: Structural and dynamic study of several magnetic systems by means of Neutron Resonant Spin Echo techniques
“ZETA” is a Neutron Resonant Spin Echo (NRSE) option which is currently installed on the thermal triple-axis spectrometer IN22 (CRG beamline at Institut Laue Langevin). To illustrate its flexibility and capabilities, I will present some results which have been collected during the last three years by making use of high resolution diffraction and spectroscopy techniques, as well as cutting-edge Time-Resolved Polarized Neutron Reflectometry (TRAC-PNR).
Three “model” systems will be presented. In a first part, I will focus on the BaM2(XO4)2 (M = Co, Ni ; X = As, P)-family which members are good prototypes of quasi-2D magnets. The effect of magnetic ordering on lattice constants is easily revealed thanks to Larmor diffraction. Moreover, the thermal evolution of optic magnon lifetime in BaNi2(PO4)2 is shown to be strongly affected by the presence of defects in its structure, raising questions about the collision rate of such excitations in non-ideal systems. Then, the spin-chain and -ladder compound Sr14Cu24O41 will be addressed. I first focus on the study of the sharp inelastic peak associated with the spin gap in the ladders spectrum and introduce a method capable of showing directly the degeneracy of the associated spin transition. An attempt to evaluate its intrinsic linewidth will be described and the effect of different charge ordering processes on the material crystallographic structure. Ultimately, I show how we can adapt the existing instrumentation to perform TRAC-PNR experiments, using the so-called MIEZE principle, for the study of a magnetic multilayer which can present interesting properties for applications in spintronics.
- Physics HS3
- Garching, Garching, Deutschland
- N. Martin, Forschungsneutronenquelle Heinz Maier-Leibnitz, Technische Universität München
- TUM/FRM II