Dresden 2014 – wissenschaftliches Programm
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MI: Fachverband Mikrosonden
MI 2: Untersuchung von kondensierter Materie mittels Positronen-Annihilation
MI 2.9: Vortrag
Montag, 31. März 2014, 12:45–13:00, MER 02
MnSi Single Crystal Growth - Effects of the Outgasing of Mn Studied by Positron Annihilation Spectroscopy — •Markus Reiner1,2, Wolfgang Anwand3, Andreas Bauer1, Maik Butterling3, Thomas Gigl1,2, Christian Pfleiderer1, Andreas Wagner3, and Christoph Hugenschmidt1,2 — 1Technische Univeristät München, Physik-Department, Lehrstuhl E21, James-Franck-Straße 1, 85748 Garching — 2Technische Univeristät München, ZWE FRM-II, Lichtenbergstraße 1, 85748 Garching — 3Helmholtz-Zentrum Dresden-Rossendorf, Kernphysik, Bautzner Landstraße 400, 01328 Dresden
The intermetallic B20 compound MnSi exhibits outstanding magnetic properties. Both the understanding of complex magnetic phenomena and the possible application as extremely efficient data storage material in future devices require the production of defect-free single crystalline MnSi.
For the present study, several MnSi single crystals have been grown from initial rods with a varying Mn excess in order to compensate the outgasing of Mn during crystal growth. The quality of the various crystals was examined by (coincident) Doppler broadening and positron lifetime spectroscopy. Wafers were investigated with the highly intense positron beam NEPOMUC at the FRM-II. In addition, the whole crystal rods were examined at the GIPS facility in the HZDR
The results clearly show that the open volume defects in MnSi can be efficiently reduced by inducing a slight Mn excess of several atomic percent in the initial rods used for single crystal growth.