Magnetization-Switching Study of fcc Fe–Pd Nanowire and Nanowire Arrays Studied by In-Field Magnetic Force Microscopy

Using electrodeposition into anodic aluminum oxide (AAO) membranes, we have successfully fabricated near-equiatomic Fe_48±3Pd_52±3 nanowires (NWs) with the diameter of ≈200 nm and the length of ≈3.5 μm. X-ray diffraction and transmission electron microscopy/selected-area electron diffraction analyses revealed that the as-deposited NWs are isotropic and polycrystalline with an average crystal size of 5 nm and have an fcc crystal structure. Magnetic force microscopy (MFM) on a single Fe-Pd NW revealed its single-domain behavior with the easy axis of magnetization along the long axis of the NW. The magnetizationswitching behavior of a single Fe-Pd NW studied with the MFM suggested a square-shaped magnetization curve (M/M_s = 1) with H_CI ≈ 3.2 kA/m. In addition, using in-field MFM techniques, the effects of dipolar interactions in an Fe-Pd array of NWs still embedded in the AAO were determined. It was found that the dipolar interactions greatly reduce the parameters of the magnetization hysteresis loop, such as the coercivity, the remanence, and the switching-field distribution of the Fe-Pd NW array.