Barium ferrate

The best known oxoanion of iron is the ferrate(VI) prepared by oxidizing a suspension of hydrous iron(III) oxide in concentrated alkah with potassium hypochlorite or by anodic oxidation of iron in concentrated alkah. Crystals of potassium ferrate [13718-66-6], K FeO, are deep purple, orthorhombic, and contain discrete tetrahedral [FeOJ anions. Barium ferrate [13773-23A] can be precipitated from solutions of soluble ferrate salts. 

Barium ferrate, BaFe04, like barium sulfate and barium chromate, is insoluble and is the most stable of the ferrates. Dissolve the potassium salt in about ten times its weight of water, filter it through a filter paper... 

Barium ferrate suspended in glacial acetic acid oxidizes squalene to monoepoxysqualene in low yield.306 Potassium ferrate is unreactive towards alkanes, but when reduced by oxalic acid it... 

Iron trioxide can only exist in combination with bases, as, for example, in barium ferrate, BaFe04. Ruthenium does not yield a separate trioxide either, although its derivatives are better known than... 

Barium ferrate, BaFe03, is best produced by heating a mixture of ferric and barium hydroxides to 600° C. in a current of oxygen.8 It is a friable, black, amorphous substance, stable up to about 650° C. Cold water decomposes it slowly, warm water somewhat more rapidly, with evolution of oxygen. Acids readily effect its decomposition, yielding barium and ferric salts. If hydrochloric acid is used, free chlorine and oxygen are simultaneously liberated. 

The barium ferrate(IV) phase is only partly related to the strontium compound as it has a hexagonal structure instead of the cubic perovskite structure... 

Barium dioxide. See Barium peroxide Barium distearate. See Barium stearate Barium ferrate. See Barium ferrite Barium ferrite... 

Synonyms Barium ferrate Barium hexaferrite Barium iron oxide... 

Described by Salter (1869) as Produced by adding aqueous ferrate of potash to an excess of dilute solutions of baryta salts. The exact composition of the resulting pigment is unknown, but is likely to be a barium ferrate or barium potassium ferrate. 

A brief review of ferrates(VI) Coord.Chem.Rev. l 91A) 5 ) gives the magnetic moment of the barium ferrate as 3. IS pg. This confirms the d configuration of the tetrahedral ion. This is also indicated by the three spin-allowed d-d bands at 786, 510 and 226 nm. If the solution obtained in the preparation is quickly transferred to a vacuum uv cell the spectrum can be recorded. DTA of the barium salt and other ferrates are also referred to in the above reference. 

Zan] Zanne, M., Gleitzer, C., Aubry, J., Barium Ferrates(III-IV) at Ba/Fe=l Phase Diagram and Property Diagram , (in French), Bull. Soc. Chim. Fr, (7), 2451-2455 (1971) (Phase Relations, Phase Diagram, Electr. Prop., Magn. Prop., Experimental 20)... 

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