Berlin 2008 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 32: Postersession II: Spinstruct./Phase Trans. (1-10); Spinelectronics (11-15); Thin Films (16 - 36); Particles/Clusters (37-45); Multiferroics (46-54); Spindynamics/Spin Torque (55 - 76); Post Deadlines (77-79)

MA 32.47: Poster

Freitag, 29. Februar 2008, 11:15–14:00, Poster E

Magnetic and thermodynamic studies of R(Mn,Fe,Co)₂O₅, (Bi,Sm)MnO₃ and Bi(Fe,Ni)O₃ — •Norman Leps¹, Nadja Wizent¹, Dmitri Souptel¹, Rüdiger Klingeler¹, Christian Hess¹, Natalia Tristan¹, Günter Behr¹, Matthias Lutz¹, Sang Wook Cheong², and Bernd Büchner¹ — ¹IFW-Dresden, P.O. Box 270116, D-01171 Dresden — ²Department of Physics and Astronomy, Rutgers, The State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ 08854-8019 USA

The simultaneous appearance of magnetic and electric ordering in frustrated spin systems offers the potential for novel electromagnetic building blocks. Among the frustrated spin systems rare earth manganates RMn₂O₃ (R=Y, Tb, Ho) and the perovskites BiMnO₃ and BiFeO₃ exhibit multiferroic properties. The magneto-electric coupling, however, is very small in all cases and the frustrated antiferromagnetism delimits the achievable tuning of the magnetization via an external electrical field, or vice versa, the spontaneous polarization via a magnetic field. We hence have systematically studied the effect of different doping on both the magnetic and the A-sites of the respective materials. To be specific, the influence of the cations was investigated by partially substituting Mn by Fe or Co in RMn₂O₅ and Ni in BiMnO₃, respectively. The role of the electronic subsystem was investigated by partial substitution of Bi by Sm in BiFeO₃. Our magnetization and specific heat measurements of the doped materials provide the phase diagrams which are discussed with respect to the multiferroic properties.