Synthesis of High Coercivity Core–Shell Nanorods Based on Nickel and Cobalt and Their Magnetic Properties

Abstract

Hybrid magnetic nanostructures with high coercivity have immense application potential in various fields. Nickel (Ni) electrodeposited inside Cobalt (Co) nanotubes (a new system named Ni @ Co nanorods) were fabricated using a two-step potentiostatic electrodeposition method. Ni @ Co nanorods were crystalline, and they have an average diameter of 150 nm and length of ~15 μm. The X-ray diffraction studies revealed the existence of two separate phases corresponding to Ni and Co. Ni @ Co nanorods exhibited a very high longitudinal coercivity. The general mobility-assisted growth mechanism proposed for the growth of one-dimensional nanostructures inside nano porous alumina during potentiostatic electrodeposition is found to be valid in this case too.

Comprehensive Study of Ni Nanotubes for Bioapplications: From Synthesis to Payloads Attaching

“…It should be noted that the loop measured at different directions of the magnetic field relative to the main axis of the NTs has different character, which indicates the presence of the magnetic anisotropy in the samples: coercivity and squarness value for parallel orientation ( c|| = 330 Oe, r|| / s|| = 0.39) of the field relative to the NTs axis is several times higher than the values for the perpendicular field direction ( c⊥ = 130 Oe, r⊥ / s⊥ = 0.09). The anisotropy of the magnetic properties could be defined by either crystalline anisotropy, detected in the X-ray analysis, or shape anisotropy, caused by the fact that in an external magnetic field NTs with high aspect ratio (∼100) need higher energy of demagnetization along their axis than in the perpendicular direction of the field [15,17].…”

“…This problem does not allow making a sufficient force for the blood flow resistance. Nanowires and nanotubes (NTs) allow overcoming typical limitations for nanoparticles due to their elongated form and anisotropy of magnetic properties [11][12][13][14][15][16][17][18][19]. In comparison with nanowires, NTs have some potential advantages.…”

“…In comparison with nanowires, NTs have some potential advantages. The absence of magnetic core makes it possible to create nanostructures with uniform magnetic field [15]. A lower density enables them to float in liquids (including the biological ones).…”

Hydrogenation of Styrene Oxide to 2-Phenylethanol over Nanocrystalline Ni Prepared by Ethylene Glycol Reduction Method

“…Analysis of magnetic measurements shows that Raney Ni has coercivity of 330 Oe, whereas that of bulk Ni is 0.7 Oe [25]. Observed change in the coercivity can be attributed to the different grain diameters in Raney Ni and in bulk Ni.…”

Synthesis of nanoporous chromium film by DC electrodeposition on aluminum substrate

“…The fabrication of PAA is a cheap process, easy technology and high-throughput [7]. Many metals nanostructures were deposited on the PAA surface such as Au, Ni, Ag and Zn by different methods [8][9][10][11]. Among these methods, DC electrodeposition is widely employed to deposit nanostructures in PAA templates due to its inexpensive procedure [13,14].…”