1284.    GULBRANSEN, E. A., AND RUKA, A. R.  Kinetics of Solid-Phase Reactions in Oxide Films on Iron.  Reversible Transformation at or Near 570°.  Jour. Metals, vol. 188, Trans., 1950, pp. 1500-1508; Chem. Abs., vol. 45, 1951, p. 426.

        Forward and reverse reactions, Fe₃O₄+Fe=4 FeO, were studied by electron-diffraction methods.  In thin films the forward reaction occurs at temperatures 170° below the equilibrium value.  The mechanism of the forward reaction is governed by the diffusion of Fe.  Studies of the reverse reaction as a function of time, temperature, and oxide composition indicate that a process of nucleation and growth is rate controlling.