Development of half-metallic ultrathin Fe3O4 films for spin-transport devices

We attempted to fabricate a high-quality Fe3O4 film while satisfying both low-thermal preparation (less than or equal to573 K) and film thinness (less than or equal to500 Angstrom). X-ray diffractometry showed that our prepared Fe3O4 film was epitaxially grown onto a MgO (100) substrate. The saturation magnetization, resistivity, and Verwey point were, respectively, similar to438 emu/cm(3), similar to10 000 mu Omega cm, and similar to110 K. These values were comparable to those of the Fe3O4 bulk. Our experimental results suggested that a high-quality Fe3O4 film could be obtained even under the crucial conditions of the deposition temperature being low (similar to523 K) and the film being ultrathinned (similar to100 Angstrom). (C) 2002 American Institute of Physics.