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TT: Fachverband Tiefe Temperaturen

TT 44: Poster Session Correlated Electrons

TT 44.12: Poster

Thursday, March 17, 2011, 10:00–13:00, P1

Exotic Heavy-Fermion Behaviour of the Filled Skutterudite SmPt₄Ge₁₂ — •Roman Gumeniuk¹, Walter Schnelle¹, Michael Nicklas¹, Helge Rosner¹, Michael Schöneich², and Andreas Leithe-Jasper¹ — ¹MPI Chemische Physik fester Stoffe, Dresden — ²Anorganische Chemie, TU Dresden

Samarium-filled platinum-germanium skutterudite SmPt₄Ge₁₂ was prepared at high pressure and temperature (5.0 GPa, 1070 K). The compound is isotypic with LaFe₄P₁₂ (cubic, space group Im3, a = 8.6069(4) Å). X-ray absorption spectroscopy measurements show that samarium in SmPt₄Ge₁₂ has a temperature-independent intermediate valence (ν = 2.90 ± 0.03). Van-Vleck paramagnetism is observed above ∼50 K. The low-temperature specific heat displays a broad anomaly around at 2.9 K and a large linear coefficient γ′ = 450 mJ mol⁻¹K⁻² suggesting heavy-fermion behaviour. Electrical resistivity shows a temperature dependence reminiscent of the Kondo effect. Density functional calculations result in an electronic structure that is, apart from the Sm 4f contributions, very similar to LaPt₄Ge₁₂.