<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Controlled solvothermal preparation of highly crystalline CoFe<sub>2</sub>O<sub>4</sub> (I) and amorphous CoFe<sub>2</sub>O<sub>n</sub> (II; n ≈3.66) are performed by using aqueous resp.</p> </abstract>