HIGH-VACANCY-CONTENT MAGNETITES AND ZINC-BEARING FERRITES FROM IRON(III) TARTRATE IN STRONGLY ALKALINE-SOLUTION

High‐vacancy‐content magnetites with particle size in the range of 20 to 150 nm can be precipitated as stable products in the clear and strongly alkaline solution of iron(III) tartrate and dextrose at 100°C, although Fe(III) ions in alkaline solution have been reported previously to form only α‐FeO(OH) and α‐Fe2O3. When Zn(II) ions were present in the reaction solutions, high‐vacancy‐content Zn(II)‐bearing ferrites represented by (ZnFe2O4)x‐(Fe3O4)y‐(γ‐Fe2O3)z, where x+y+z= 1, were obtained in the strongly alkaline solutions. The Fe(II) ions, which were formed by the reduction of Fe(III) ions with dextrose, accelerate the crystallization of the spinel structure. Copyright © 1990, Wiley Blackwell. All rights reserved