Magnetic properties of nanostructured wires deposited on the side edge of patterned thin film

In the present study, magnetic nanowires with various cross-sectional dimensions have been fabricated by evaporating a magnetic material on the side edges of the patterned nonmagnetic thin film. The method allows the lengths of the two short axes to be defined precisely by controlling the thickness of the oxide (W-x) and magnetic material (W-y). The MFM images of the produced Co wires (2 mu m length) with dimensions of W-x=W-y=200 nm and W-x=W-y=50 nm present the single domain configuration. The MFM and magnetoresistance (MR) measurement demonstrate that the longitudinal magnetization switching field increases with the decrease of W-x and W-y, which becomes 1.3 kOe for wires with W-x=W-y=50 nm. The profile of the MR hysteresis suggests that considerable coherent rotation takes place before the irreversible longitudinal switching. Transverse saturation fields larger than 6 kOe were measured in the orthogonal two short axis directions, which confirms the successful fabrication of three-dimensional wires with comparable cross-sectional dimensions. (C) 2000 American Institute of Physics. [S0021-8979(00)60608-4].