Effect of aspect ratio on the magnetic properties of nickel nanowires

Abstract

Nickel nanowires with a diameter of ∼200 nm were prepared using the electrodeposition technique. The length of the nanowires was varied from 0.7 to 5.6 μm, which corresponds to the change in the aspect ratio from 3.5 to 28. Field emission scanning electron microscopy and x-ray diffraction spectra confirm the formation of nickel nanowires. In-plane and out-of-plane coercivity and remanence of the samples determined from direct current magnetic hysteresis loops suggest the magnetic easy axis of the nanowires along their transverse direction. As a result, magnetic hardness along the axis of the nanowires is higher than that perpendicular to it. The temperature dependence (80 K≤T≤350 K) of coercivity and squareness ratio of the samples has also been studied in detail. The vortex configuration of magnetization in the individual nanowires along with magnetostatic interaction among them has been suggested as the possible explanation for the observed magnetic properties of these nanowires in the present study.

Effect of <inline-formula> <tex-math notation="TeX">\(\alpha \) </tex-math></inline-formula>-Particle Irradiation on the Magnetic Properties of Ni Nanowires

“…The thickness of an alumina membrane was ∼50 μm with nanosized pores of an average diameter of ∼100 nm and a pore density of 10 9 /cm 2 . The AAO templates with one side coated with a conductive gold (Au) layer of 0.1 μm thickness grown by thermal evaporation technique were used as a working electrode in the electrodeposition process to fabricate the highly ordered arrays of Ni NWs [5], [10], [13].…”

“…Highly ordered arrays of such NWs show novel and interesting magnetic properties different from those of bulk and thin films, and sensitively depend on their sizes, shapes, and the interactions among them [5]- [7]. Among the various methods for preparing NWs, electrodeposition is widely used because of its simplicity and low cost.…”

Electrochemical synthesis of nickel hexacyanoferrate nanoarrays with dots, rods and nanotubes morphology using a porous alumina template

“…A length/diameter aspect ratio of 30-70 and high density of Ni-NR and NiHCF structures makes their appearance rather as more brush-like than rod morphology. The grouping of magnetic nanorods could significantly affect their properties such as magnetic or catalytic, hence for some applications it is beneficial to decrease the length of nanorods and increase their inter-distance, which is allowed by this approach [30].…”

Effect of Aspect Ratio and Temperature on Magnetic Properties of Permalloy Nanowires

“…[1][2][3][4] Highly ordered arrays of such nanowires show novel and interesting magnetic properties different from those of bulk and thin films and sensitively depend on their sizes, shapes, and the interactions among them. [5][6][7] Among the various methods for preparing nanowires, electrodeposition is widely used because of its simplicity and low cost. In this method, various magnetic materials such as Fe, Co, Ni, and their alloys were embedded into the nanopores of silica, alumina, or polycarbonate membranes by the electrodeposition technique.…”