SOLVOLYTIC DISPROPORTIONATION OF MIXED-VALENCE COMPOUNDS. II. Tb11O20. .

Article abstract of DOI:10.1016/0022-4596(88)90303-9

The intermediate higher oxides of terbium are solvolytically disproportionated in acid solution to yield Tb**3** plus (aq) ions and a residue of TbO//2(c). The starting material and the final solid product have fluorite-like structures requiring no reconstruction of the cation substructure. Tb//1//1O//2//0 was leached with a mixture of concentrated hydrochloric and acetic acids and the product examined utilizing electron microscopy to reveal the mechanism of the reaction. It is apparent that all the oxide is dissolved from selected reaction pits to yield Tb**3** plus (aq) ions and H//2O. This dissolution is accompanied by oxygen transport into remote regions where Tb//1//1O//2//0 is oxidized to TbO//2.