Regensburg 2010 – scientific programme
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MA: Fachverband Magnetismus
MA 27: Spin Structures and Magnetic Phase Transitions
MA 27.2: Talk
Thursday, March 25, 2010, 17:30–17:45, H10
Nature of the Magnetic Order and Magnetic Interactions in BaMn2As2 — •Yogesh Singh1, Philipp Gegenwart1, David Johnston2, Rob McQueeney2, Alan Goldman2, and Bella Lake3 — 11. Physikalisches Institut, Georg August Universitaet, Goettingen, Friedrich Hund Platz 1, 37077, Goettingen, Germany. — 2Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA. — 3Helmholtz-Zentrum Berlin für Materialien und Energie (HZB), Glienicker Straße 100, 14109 Berlin, Germany.
The recent discovery of high temperature superconductivity in several structure classes containing FeAs-layers has led to a flurry of activity not seen since the discovery of CuO-based high temperature superconductors more than 20 years ago. In an attempt to discover new materials related to these FeAs-based systems we have studied in detail the properties of BaMn2As2 which is iso-structural to tetragonal BaFe2As2. In this talk I will present our magnetic, thermal, transport, and neutron diffraction and scattering studies on polycrystalline and single crystalline samples of BaMn2As2. We find that BaMn2As2 undergoes a transition into a G-type antiferromagnetic state below TN = 620 K with the ordering direction being the c axis. Our estimates of the magnetic interactions indicate that BaMn2As2 is a quasi-two-dimensional magnetic system with frustrating antiferromagnetic nearest-neighbor (J1) and next-nearest-neighbor (J2) in-plane interactions.