Berlin 2018 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MA: Fachverband Magnetismus
MA 50: Soft and hard permanent magnets
MA 50.3: Vortrag
Donnerstag, 15. März 2018, 15:30–15:45, EB 301
Li[Li1−xCox]AE2N2 (AE = Ca, Sr): New examples for magnetically anisotropic transition metals in linear coordination — •Tanita J. Ballé1, Peter Höhn2, and Anton Jesche1 — 1EP VI, Center for Electronic Correlations and Magnetism, Augsburg University, 86159 Augsburg, Germany — 2Max-Plack-Institut für Chemische Physik fester Stoffe, Nöthnitzer Str. 40, 01187 Dresden, Germany
Li2[Li1−xFex]N is one of the scarce rare-earth free hard magnets and shows a huge magnetic anisotropy and the highest known coercivity field of more than 11 T! These properties are attributed to the unquenched orbital moment of iron, enabled by the perfect linear, twofold coordination of iron between nitrogen [1]. In order to investigate the necessity as well as sufficiency of this geometrical motive, we studied similar compounds [2]. We will show that large coercivity fields are not restricted to iron. Isothermal and temperature dependent magnetic measurements were performed on Li[Li1−xCox]AE2N2, which contains cobalt in linear coordination. Ferromagentic ground states with a coercivity of ∼ 0.5 T are observed at 2 K. The Hysteresis vanishes at 76 K for AE = Ca and 43 K for AE = Sr, respectively, and is clearly reflected in the temperature dependence of the magnetization. We conclude that the structural motive of a transition metal in linear coordination with only two neighbours, allows to predict materials with stable magnetic properties. [1] A. Jesche et al. Nat. Commun. 5:3333. doi: 10.1038/ncomms4333 (2014) [2] P. Höhn, TJB et al. Inorganics 4, 42 (2016)