Röntgenographische Untersuchungen zum Ablauf einer Redoxreaktion im Bereich ternärer Eisensulfide

X‐ray Diffraction Analysis of a Redox Process Concerning Ternary Iron Sulfides The mixed‐valent ternary iron sulfide Cs₃Fe₂S₄ reacts with water to the structurally related sulfide CsFeS₂. Hydrogen arises during this reaction. Moreover hydroxide and cesium ions were detected in the aqueous phase. Using X‐ray diffraction, the process was followed up by a time lag reaction of Cs₃Fe₂S₄ in an argon atmosphere with defined content of water. Here, cesium hydoxide monohydrate was found as an intermediate product: Cs₃Fe₂S₄ + 2 H₂O → 2 CsFeS₂ + CsH₃O₂ + ¹/₂ H₂.