Regensburg 2019 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

MA: Fachverband Magnetismus

MA 51: Magnetism Poster B

MA 51.66: Poster

Donnerstag, 4. April 2019, 15:00–18:00, Poster C

Local magnetic properties and couplings of Co_2−xMn_xB: A ⁵⁹Co and ⁵⁵Mn zero field NMR study — •P. Fritsch¹, F. Hammerath¹, S. Ener², M. Fires², I. Opahle², E. Simon^2,3, S. Wurmehl^1,4, H. Zhang², and O. Gutfleisch^2,5 — ¹Leibniz Institute for Solid State Research IFW, Dresden, Germany — ²Department of Material Science, Technische Universität Darmstadt, Darmstadt, Germany — ³Department of Theoretical Physics, Budapest University of Technology and Economics, Budapest, Hungary — ⁴Institute for Solid State Physics, Technische Universität Dresden, Dresden, Germany — ⁵Fraunhofer-Projektgruppe für Wertstoffkreisläufe und Ressourcenstratgie IWKS, Hanau, Germany

Co₂B and its substitution variants show a magnetovolume effect around T_C, which is promising for magnetocaloric applications and the generation of thermomagnetic power. A series of Co_2−xMn_xB alloys was synthesized and the macroscopic magnetic properties were investigated. An anomalous behaviour of spontaneous magnetization and T_C with increasing Mn content as a result of competing exchange interactions. Zero field Nuclear Magnetic Resonance spectroscopy (NMR) was measured for ⁵⁹Co and ⁵⁵Mn nuclei to determine the element specific magnetic moments supported by density functional theory (DFT) calculations. A mutual combination of experimental and theoretical methods reveals that the observed anomaly originates in complex magnetic coupling, as shown by the exchange interactions.

S. Ener et al., accepted by Acta Materialia (2018)