Effect of thermo-chemical treatment on magnetic and spin-transport properties of epitaxial Fe3O4 (1Â 0Â 0)/MgO films

The effect of thermo-chemical treatment on the magnetic and spin-transport properties of epitaxial Fe3O4 (1 0 0) thin films grown on MgO (1 0 0) substrates was investigated. We found that the magnetization of the films remarkably increases after just 4 min of annealing in air at 250 °C. In situ resistance measurements were carried out during the treatment and the contribution of domains and antiphase boundaries on the change in resistance was clarified. A model involving a change in the antiferromagnetic coupling at the antiphase boundaries during the treatment is proposed.