Oxidation Kinetics Study of Finely Divided Magnetites Substituted for Aluminium and Chromium

Abstract

It has long been known (1–3) that the cubic iron sesquioxide γFe2O3 only forms during low-temperature oxidation of finely-divided magnetites. However, “cubic” iron sesquioxides substituted for trivalent ions such as aluminium or chromium have been described only recently by Rousset (4–5). This difference may be explained by the fact that substituted magnetites prepared at temperatures close to 1000°C, by usual procedures are only slightly reactive towards oxygen.