Nanoscale Fe3O4 epitaxial thin film has been synthesized on MgO/GaAs(100) spintronic heterostructure, and studied with X-ray magnetic circular dichroism (XMCD). We have observed a total magnetic moment of (3.32 +- 0.1) uB/f.u., retaining 83% of the b
ulk value. Unquenched orbital moment of (0.47 +- 0.05) uB/f.u. has been confirmed by carefully applying the sum rule. The results offer direct experimental evidence of the bulk-like total magnetic moment and a large orbital moment in the nanoscale fully epitaxial Fe3O4/MgO/GaAs(100) heterostructure, which is significant for spintronics applications.
The spin and orbital magnetic moments of the Fe3O4 epitaxial ultrathin film synthesized by plasma assisted simultaneous oxidization on MgO(100) have been studied with X-ray magnetic circular dichroism (XMCD). The ultrathin film retains a rather large
total magnetic moment, i.e. (2.7+-0.15) uB/f.u., which is ~ 70% of that for the bulk-like Fe3O4. A significant unquenched orbital moment up to (0.54+-0.05) uB/f.u. was observed, which could come from the symmetry breaking at the Fe3O4/MgO interface. Such sizable orbital moment will add capacities to the Fe3O4-based spintronics devices in the magnetization reversal by the electric field.
