ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Synthesis of BaFe₁₂0₁₉ Powders in Molten Alkali Metal Chlorides

V. Daněk and Ž. Lubyová

Institute of Inorganic Chemistry, Slovak Academy of Sciences, SK-842 36 Bratislava

Abstract: Very fine powders of barium ferrite BaFe₁₂O₁₉ were prepared by the reaction of iron(III) oxide and barium carbonate in the medium of molten alkali metal chlorides. The effect of the temperature and the time of the isothermal heating on the conversion degree and the size of the BaFe₁₂O₁₉ crystals was studied. BaFe₁₂O₁₉ originates already at the temperature of 800° C, however it becomes to be the dominating reaction product above the temperature of 850°C and the heating time of 1 h. It was found that at the temperature of 850° C and the reaction time of 0.5-2 h the rate of the BaFe₁₂O₁₉ crystal growth is controlled by surface chemical reaction. The activation energy of the BaFe₁₂O₁₉ formation has the value ∆ E = 300 kJ mol^-1 corresponding to the reaction in the liquid medium as the rate-limiting process.

Full paper in Portable Document Format: 484a245.pdf

Chemical Papers 48 (4) 245–247 (1994)