Influence of reducing thermo-chemical treatment on magnetic properties of magnetite Fe3O4 (1Â 0Â 0) epitaxial films

The effect of low temperature annealing in a reducing atmosphere on the magnetic properties of epitaxial magnetite (1 0 0) films grown on MgO (1 0 0) substrate was investigated. We found that the magnetization of the films increases and the coercivity decreases with treatment in CO at the partial pressure of 1.01×105 Pa at 250 °C. The annealed films show a sharp Verwey transition. Marginal change in the stoichiometry of the films is not the reason for the magnetization enhancement. It is thought that the decrease of antiphase boundaries density and the oxygen vacancies produced at the antiphase boundaries are responsible for the observed results.