Fabrication of magnetic nanostructures using electron beam induced chemical vapour deposition

Finely focused electron beam induced chemical vapour deposition with iron carbonyl gas, Fe(CO)(5), was carried out at room temperature to fabricate desired-shape nanostructures such as dots, rods and rings. The as-formed structures exhibited an amorphous phase containing iron, carbon and oxygen elements in the whole volume and iron oxide nanocrystals existed near their surfaces. A post-deposition heat treatment at about 600 degrees C resulted in the transformation into a crystalline alpha-iron phase, while their shapes were maintained. The residual magnetic flux density B, of the as-formed and alpha-iron nanorods was quantitatively measured by electron holography after magnetization, showing that their B, values were similar to those of iron micro-powders, although the alpha-iron nanorod has a smaller B, value than the as-formed nanorod.