Syncrystallization of CoFe 2O 4 from ferric and cobaltous chlorides: Physical properties of the precipitate

Abstract

The precipitate CoFe 2O 4 obtained from cobaltous and ferric chlorides and potassium hydroxide is a well-crystallized spinel phase, indicating that the term “coprecipitation” is not suitable for describing this synthesis. The term “syncrystallization,” which means crystallization of a definite compound directly during the precipitation, is preferred. The fine powder of CoFe 2O 4 is very reactive toward oxygen. CoFe 2O 4 contains mixed valences Co 2+ and Co(III) between 100 and 600°C, which has a great influence on the crystallographic parameter and the saturation magnetization.