ausblenden:
Schlagwörter:
-
Zusammenfassung:
The novel host-guest compound [Cs6Cl][Fe24Se26] (I4/mmm; a=11.0991(9),
c=22.143(2)angstrom) was obtained by reacting Cs2Se, CsCl, Fe, and Se in
closed ampoules. This is the first member of a family of compounds with
unique Fe-Se topology, which consists of edge-sharing, extended fused
cubane [Fe8Se6Se8/3] blocks that host a guest complex ion, [Cs6Cl](5+).
Thus Fe is tetrahedrally coordinated and divalent with strong exchange
couplings, which results in an ordered antiferromagnetic state below
T-N=221K. At low temperatures, a distribution of hyperfine fields in the
Mossbauer spectra suggests a structural distortion or a complex spin
structure. With its strong Fe-Se covalency, the compound is close to
electronic itinerancy and is, therefore, prone to exhibit tunable
properties.