DPG Phi
Verhandlungen
Verhandlungen
DPG

Dresden 2003 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

MA: Magnetismus

MA 14: Poster: Schichten(1-31), Spinabh.Trsp.(32-47), Exch.Bias(48-54), Spindyn.(55-64), Mikromag.(65-76), Partikel(77-88), Oflmag.(89-92), Spinelektr.(93-98), Elektr.Theo.(99-103), Mikromag+PhasÜ+Aniso.(104-122), MagnMat.(123-134), Messm+Mol-Mag.(135-139), Kondo(140-151)

MA 14.113: Poster

Tuesday, March 25, 2003, 15:15–19:15, Zelt

Structural and magnetic properties of NaFe4Sb12 and KFe4Sb12 — •Andreas Leithe-Jasper1, Walter Schnelle1, Narayani Senthilkumaran1, Annegrit Rabis1, Andrei Gippius1,2, Michael Baenitz1, and Yuri Grin11MPI für Chemische Physik fester Stoffe, Nöthnitzer Str. 40, D-01187 Dresden, Germany — 2Moscow State University, Faculty of Physics, Russia

Alkali metal iron antimonides NaFe4Sb12 and KFe4Sb12 with filled skutterudite structure have been synthesized. Chemical analysis of bulk and EPMA of single crystalline material confirm the stoichiometric composition. Powder XRD data give cubic (space group Im3) lattice parameters a = 9.1767(5) Å for NaFe4Sb12 and a = 9.1994(5) Å for KFe4Sb12, respectively. Single crystal XRD analysis of NaFe4Sb12 (R = 0.027) corroborates full occupancy of the Na 2a position inside the large voids formed by tilted [FeSb6] octahedra. Similar to other filling atoms in skutterudite structures [1] the Na atoms show a large displacement parameter. The complex interplay of the parent iron-antimony based polyanionic substructure [Fe4Sb12] with the filler cations Na+ and K+ gives rise to interesting physical properties. Ferromagnetic order with µsat/Fe-atom ≈ 0.4 µB is found in both compounds at TC ≈ 85 K while no magnetic order is found in isostructural Ba and Ca compounds [1]. A paramagnetic effective moment of 1.6–1.8 µB/Fe-atom and Θ ≈ TC is found in the alkali-filled compounds. Metallic conductivity with ρ≈ 1200 µΩ cm at 300 K with a kink at TC is observed. Heat capacity measurements reveal a small peak at TC and confirm the bulk character of the ferromagnetism.

[1] C. Uher, Semiconductors and Semimetals 68, 139 (2001).

100% | Mobile Layout | Deutsche Version | Contact/Imprint/Privacy
DPG-Physik > DPG-Verhandlungen > 2003 > Dresden