Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

TT: Fachverband Tiefe Temperaturen

TT 22: CE: Spin Systems and Itinerant Magnets

TT 22.10: Vortrag

Mittwoch, 24. März 2010, 12:00–12:15, H21

Quantum Phase Transitions in Single-Crystal Mn_1−xFe_xSi and Mn_1−xCo_xSi: II. Small Angle Neutron Scattering — •Tim Adams¹, Sebastian Mühlbauer¹, Andreas Bauer¹, Andreas Neubauer¹, Christian Franz¹, Robert Georgii², Peter Böni¹, and Christian Pfleiderer¹ — ¹Technische Universität München, Germany — ²Forschungsneutronenquelle Heinz Maier-Leibnitz, Garching, Germany

We report a comprehensive small angle neutron scattering study of the evolution of the magnetic phase diagram in Mn_1−xFe_xSi and Mn_1−xCo_xSi. With increasing concentration x the magnetic phase diagram remains essentially unchanged, exhibiting a well defined helimagnetic, conical and Skyrmion lattice phase up to X≈ 0.5x_c, where x_c is the critical concentration for which the helimagnetic transition temperature vanishes. Surprisingly, for concentrations x→ x_c the magnetisation, susceptibility and specific heat are still akin the magnetic phase diagram of pure MnSi, but small angle neutron scattering suggests the emergence of complex spin textures. Similarities and differences with the pressure-temperature phase diagram of pure MnSi and the doped semiconductor Fe_1−xCo_xSi will be discussed.