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Abstract

K₃CrTe₃O₁₂, Na₃CrTe₃O₁₂, and NaCrTe₂O₈ were obtained by reacting telluric acid or amorphous potassium tellurate with molten alkali dichromates, and their structural and magnetic properties were studied. The three substances are paramagnetic, with magnetic moments corresponding to the chromium oxidation state III. The sodium compounds obey the Curie-Weiss law up to the temperature of decomposition, the potassium compound follows this law up to a temperature of 800 K, above which the magnetic moment of chromium decreases probably on account of a partial reversible oxidation of chromium by the tellurium(VI) present. The three substances investigated were indexed in the tetragonal system and their lattice parameters were calculated. The two sodium salts involve the same basic structure motiv, viz. Te₁₂O₄₈^24-.