High-vacancy-content zinc(II)-bearing ferrites from iron(III) tartrate in strongly alkaline solutions

Abstract

Zn^II-bearing ferrites with spinel-type structure have been synthesized in strongly alkaline solutions of iron(III) tartrate containing Zn^II ions at 100 °C. The Zn^II-bearing ferrites contain few Fe^IIions, but have a high cation vacancy content (high-vacancy-content Zn^II-bearing ferrite). The ferrites are solid solutions represented by x(ZnFe₂O₄)–y(Fe₃O₄)-Z(γ-Fe₂O₃), where x+y+z= 1 (0.16⩽x⩽0.90, 0.01 ⩽y⩽ 0.02, 0.09 ⩽z⩽ 0.82). The cation vacancies are replaced with the Zn^IIions in the reaction solution, and the replaced number increases with an increase in the concentration of the Zn^II ions. The high-vacancy-content Zn^II-bearing ferrites have an ultrafine particle size, < 20 nm. The crystal growth of the ferrite particles is accelerated with the Zn^II ions in the reaction solution.