Magnetic alignment of nanowires

Spatial manipulation and ability to assemble and position nanostructures in a controlled manner so they are registered to lithographically defined contacts is a critical step toward scalable integration in high-density nanodevices. By integrating ferromagnetic ends on nanostructures and using the magnetic interaction between ferromagnetic ends and electrodes, we demonstrated assembling, positioning, and spatial manipulating of nanostructures on ferromagnetic contacts. Segmented nickel/gold/nickel (Ni/Au/ Ni) and nickel/bismuth/nickel (Ni/Bi/Ni) nanowires with controlled dimensions were fabricated by template-directed electrodeposition. One hundred percent magnetic alignment of nanostructures to the imposed magnetic fields was achieved by applying a low external magnetic field of 200 Oe. In addition, directional controllability of the magnetic assembling technique was demonstrated by assembling nanostructures with angles from 45 to 135 with respect to the electrodes. This magnetic assembly technique was shown to have potential for high-density interconnects without registration and individually addressable nanostructures with the use of different substrate architectures for two-dimensional control of nanostructures placement.