Room temperature formation of half-metallic Fe3O4 thin films for the application of spintronic devices

Half-metallic Fe3O4 films were prepared at room temperature using a rf sputtering system specially integrated with an external rf source. Primary emphasis was placed on obtaining a large amount of active oxygen radicals through an external electrode for efficient deposition. The insertion of an external electrode was found to be critical for room temperature growth of Fe3O4 thin films. The structural and electrical properties gave shift and broadening effects to the Verwey temperature at various powers. The magnetization could only be saturated when a 300 Oe field was applied along an easy axis of magnetization during growth. However, there was no sign of saturation up to 5 T under zero-field growth. (C) 2003 American Institute of Physics.