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MA: Fachverband Magnetismus
MA 3: Magnetic Materials I
MA 3.2: Talk
Monday, March 26, 2007, 10:30–10:45, H22
Investigation of Rb4(O2)3, a predicted Halfmetallic Ferromagnet — •Jürgen Winterlik1, Gerhard H. Fecher1, Claudia Felser1, Martin Jansen2, Claus Muehle2, and Franziska Emmerling3 — 1Johannes-Gutenberg-Universität Mainz — 2MPI Stuttgart — 3BAM Berlin
The black colour of Rubidium Sesquioxide Rb4(O2)3, an alkali oxide containing two superoxide anions and one peroxide anion, indicates an exceptional electronic structure compared to similar substances. Band structure calculations gave advice that Rb4(O2)3 might be an anionogenic halfmetallic ferromagnet with magnetism based on oxygen-2p-electrons.
Neutron diffraction measurements reveal that the substance crystallises in the cubic space group I-43d. Magnetic measurements of the substance, performed by SQUID magnetometry, show dominating antiferromagnetic interactions with indications of a frustrated system due to thermal hysteresis and lack of saturation. An effective moment of 1.95 µB matches the expected value of 2 µB quite well. The experimental data are compared to electronic structure calculations.