Berlin 2012 – scientific programme

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MA: Fachverband Magnetismus

MA 35: Magnetic Heusler Compounds I

MA 35.5: Talk

Wednesday, March 28, 2012, 16:15–16:30, H 0112

Curie temperatures of Mn₂CoZ inverse Heusler compounds — •Markus Meinert, Jan Schmalhorst, and Günter Reiss — Dünne Schichten und Physik der Nanostrukturen, Fakultät für Physik, Universität Bielefeld, 33501 Bielefeld

The exchange interactions and Curie temperatures of inverse Heusler compounds Mn₂CoZ (Z = Al, Ga, In, Si, Ge, Sn, Sb) with the Hg₂CuTi structure have been studied by density functional theory. Due to the direct Mn-Mn exchange interaction in Mn₂CoZ, the Curie temperature decreases, although the total moment increases when the Z valence electron number is increased. The coupling between the nearest-neighbor Mn atoms scales with the magnetic moment of the Mn atom on the C site. A negative pressure dependence of the Curie temperature is predicted, which follows from decreasing magnetic moments under pressure. Curie temperatures of more than 800 K are predicted for Mn₂CoAl (890 K), Mn₂CoGa (886 K), and Mn₂CoIn (845 K), which are in reasonable agreement with experiments.