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MA: Fachverband Magnetismus
MA 38: Electron Theory of Magnetism and Correlations
MA 38.1: Vortrag
Mittwoch, 22. März 2017, 09:30–09:45, HSZ 403
Large coercivity fields and magnetic anisotropy in Li2Sr[(Li1−xFex)N]2 — •Tanita Johanna Ballé1, Peter Höhn2, and Anton Jesche1 — 1EP VI, Center for Electronic Correlations and Magnetism, Augsburg University, 86159 Augsburg, Germany — 2Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Str. 40, 01187 Dresden, Germany
Li2(Li1−xFex)N is the material with the highest known coercivity field with a value of more than 11 T and shows huge magnetic anisotropy. These properties are attributed to an orbital contribution to the magnetic moment of iron that is unquenched due to the perfect linear, twofold coordination of iron between nitrogen [1]. Li2Sr[(Li1−xFex)N]2 provides a similar geometry. In order to evaluate the necessity as well as sufficiency of the linear, twofold coordination for the high coercivity field and anisotropy to emerge, we investigated single crystals of Li2Sr[(Li1−xFex)N]2 with x = 0.41. A thorough structural characterization was carried out by means of powder and single crystal X-Ray diffraction as well as chemical analysis. Isothermal and temperature dependent magnetization measurements were performed in the range of T = 2 K - 300 K and applied fields of up to µ0H = 7 T. A coercivity field of almost 7 T at 2 K and a high magnetic anisotropy were indeed observed. Furthermore we found an enhanced magnetic moment and magnetic susceptibility in this material that indicate a significant orbital contribution to the magnetic moment of iron. [1] A. Jesche et al., Nat. Commun. 5:3333. doi: 10.1038/ncomms4333 (2014)