Dresden 2014 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 19: Poster I

MA 19.29: Poster

Dienstag, 1. April 2014, 13:00–15:30, P1

Inelastic MIEZE Measurements — •Tobias Weber^1,2, Georg Brandl^1,2, Robert Georgii², and Peter Böni¹ — ¹Physik Department E21, Technische Universität München, 85748 Garching, Germany — ²Heinz-Maier-Leibnitz-Zentrum, Technische Universität München, 85748 Garching, Germany

We report on a further development of the MIEZE method for inelastic measurements of ferromagnetic samples. MIEZE is a spin-echo method similar to neutron resonance spin-echo (NRSE) [1], but with the entire polarisation analysis taking place before the sample, thus making it ideally suited for studying depolarising materials. The MIEZE instrument option [2] and the recent development of a triple-axis spectrometry (TAS) option at the instrument MIRA [3] made it possible to combine both methods into a single setup. Using TAS we can position the instrument at the specified (q, E) values given by the dispersion relation of the magnetic excitations and measure their linewidth using MIEZE at a higher resolution than that given by a pure TAS. Due to inelastic energy transfer at the sample, corrections have to be taken into account for calculating the focus point of the MIEZE signal. We present a theoretical model, Monte-Carlo simulations and first experimental results of our measurements.

[1] T. Keller et al., Scattering, Academic Press, London, pp. 1264-1286 (2002) [2] R. Georgii et al., Applied Physics Letters 98 073505 (2011) [3] R. Georgii et al., E21 Annual Report 2011/12, p. 43 (2013)