Synthesis and One-Dimensional Self-Assembly of Acicular Nickel Nanocrystallites under Magnetic Fields

Abstract

Polycrystalline nickel wires with an average length of 10 µm and diameter of about 200 nm were prepared at 70°C by a hydrothermal process with a 0.25 T magnetic field applied. Studies show that the magnetic field induced one-dimensional assembly of acicular Ni nanocrystallites with dimensions of 200 nm in length and 10-30 nm in diameter, leading to the formation of the polycrystalline nickel wires. Magnetic measurements show saturation magnetization (Ms) of the sample prepared in a 0.25 T external magnetic field is higher than that of the sample synthesized without an external magnetic field applied. It is suggested that the one-dimensional self-assembly of acicular nickel nanocrystallites with their magnetic easy axes [111] aligned along the magnetic line of force results in the improvement of the magnetic properties.

Ni/Ni3C Core–Shell Nanochains and Its Magnetic Properties: One-Step Synthesis at Low Temperature

“…4,5 Accordingly, a series of one-dimension (1D) nickel nanostructures including nanotubes, nanowires, nanorods, nanochains and nanoarrays have been synthesized. [6][7][8][9][10][11][12][13] A variety of one-dimensional (1D) core-shell structures were prepared to enhance the multifunctionality of these materials, and they have exhibited good characters in improving luminescent efficiency, magnetic property and as field effect transistors. [14][15][16][17] Many methods of preparation in high temperature, including a laser ablation method, a high-temperature route and a carbothermal reduction method, have been used to synthesize the core-shell nanomaterials.…”

Novel Nanotrees of Crystalline Nickel formed via Electrolytic Approach

“…It also can be found that the H C and M r values for these two sample are much higher than those for bulk nickel materials (100 Oe, 2.7 emu/g), which also can be attributed to their unique preferred orientation structures [22] and the reduced size as well as presence of hierarchical structures [7]. The less M S for these two samples compared with that for bulk nickel materials (55 emu/g) is mainly due to the spin disorder on the surface and surface oxidation [2]. The M-H hysteresis loops of two nickel samples are all symmetric in shape with respect to zero magnetic field.…”

“…Nanoscale metal materials with different dimensions and shapes have attracted intensive interest due to their excellent electronic, magnetic, catalytic, optical properties and promising applications in many fields such as high-density magnetic recording, catalysis, biological labeling, optoelectronics, surface-enhanced Raman scattering (SERS), and so on [1][2][3][4][5]. During the past several years, various morphologies of nanoscale nickel (Ni) such as nanoparticles, nanoplates, hexagonal nanodisks, nanotubes, nanowires, hollow octahedrons, concave polyhedrons, nanowalls and nanostrips, have indeed been synthesized [6][7][8][9][10].…”

Preparation and growth mechanism of nickel nanowires under applied magnetic field

“…with an average length of 10 ȝP and a diameter of about 200 nm, using PEG and CTAB surfactant in a sealed autoclave under an external magnetic field, under high temperature and pressure [16]. Although Gong et al synthesized Ni nanowires under normal pressure, ethylene glycol was used as the solvent [17].…”