Abstract:
The densely packed arrays of Ni nanowires of 70 nm diameter and 6–12 mm length were obtained via
electrodeposition into porous alumina membranes (PAAMs) of 55–75 mm thickness. The morphology,
microstructure and magnetic properties between the room and liquid-helium temperature of Ni
nanowires in PAAMs have been investigated using scanning electron microscopy, X-ray diffraction and
vibrating sample magnetometry. The crystal structure of the Ni nanowires is fcc with (220) preferred
orientation. The magnetic characteristics of the Ni nanowires in PAAMs were compared with the same
characteristics of bulk Ni and with other researchers' data. The effect of the porous alumina membrane
and the Ni nanowires synthesis conditions on the magnetic characteristics of Ni nanowire arrays has
been studied. The coercivity reached more than 750 kOe and the squareness ratio up to 0.65 under the
proposed optimal synthesis conditions for Ni nanowires. Magnetic parameters of the densely packed
arrays of Ni nanowires allow using them in magnetic recording media, hard disk drives, storage systems
and sensors. In addition, such structures are of considerable interest for basic research on
nanomagnetism which is significantly different from the magnetic properties of bulk and thin films
materials.
