Darstellung,Struktur und magnetische Eigenschaften der Natriumeisenchalkogenide Na6FeS4 und Na6FeSe4

Synthesis, Structure, and Magnetic Properties of the Sodium Iron Chalcogenides Na₆FeS₄ and Na₆FeSe₄ The compounds Na₆FeS₄ and Na₆FeSe₄ have been synthesized by fusion reactions of sodium carbonate with iron and chalcogen in a stream of hydrogen. Structural investigations on single crystals show that both compounds crystallize in an atomic arrangement isotypic with Na₆ZnO₄ (space group P6₃mc). The structure is characterized by isolated FeX₄]-tetrahedra. The magnetic susceptibilities show Curie-Weiss behaviour. The deviations at low temperatures are obviously caused by antiferromagnetic interactions.