Collect. Czech. Chem. Commun. 1983, 48, 2197-2204

On the structural and magnetic properties of K3CrTe3O12, Na3CrTe3O12 and NaCrTe2O8

Pavel Danihelka

Department of Chemistry, Institute of Mining and Metallurgy, 708 33 Ostrava


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. Te12O4824-.