Magnetic‐Field‐Induced Growth of Single‐Crystalline Fe₃O₄ Nanowires

Abstract

Single‐crystalline nanowires of Fe3O4 hydrothermally synthesized under a magnetic field are reported. The square and hexagonal crystals formed in zero applied field are shown to give way to nanowires as the magnetic field is increased. The Figure shows the situation for a 0.25 T field. The structure and magnetic properties are characterized by transmission electron microscopy, X‐ray and electron diffraction, and magnetometry.

Physical Properties of Elongated Magnetic Particles: Magnetization and Friction Coefficient Anisotropies

“…[115] Magnetite Micron-sized spheroidal magnetite particles were synthesized by Xuan et al [116] using FeCO 3 as a template via sealed thermal decomposition for 2 h at 500 8C. Wang et al [89] reported the preparation of magnetite nanowires by a hydrothermal process in the presence of an external magnetic field. Magnetite nanorods were prepared by Lian et al [117] through hydrolysis of Fe II and Fe III salt solutions containing urea.…”

“…In the literature there is a wide list of methods to produce nanowires, [89] nanocables, [90] nanotubes, [91,92] nanobelts, [93] nanocubes [94] and nanoflowers. [95] Among all of these methods, there are four that stand out: chemical precipitation and transformation, self-assembly under external magnetic fields, electrochemical deposition and polyol techniques.…”

A Low-Cost and High-Yield Production of Magnetite Nanorods With High Saturation Magnetization

“…A most synthetic method for magnetite NPs is usually carried out by the aqueous coprecipitation of Fe 2+ and Fe 3+ [12]. However, magnetic-field induction [13][14][15], chemical vapor deposition [16][17][18][19] and hard templated synthetic methods [20][21][22] have also been developed to fabricate 1D magnetites. The above methods for 1D magnetite usually need some special equipments such as high temperature furnaces and magnetic devices which cause a complex and tedious synthesis process.…”

The Fabrication and Magnetic Properties of Ni Fibers Synthesized Under External Magnetic Fields

“…For example, Niu et al and Wang et al fabricated polycrystalline Co, Ni, and single crystalline Fe 3 O 4 wires using the self-assembly of nanocrystallites under external magnetic fields. [12][13][14] Zhang et al prepared chainlike and ringlike NiZn ferrite nanostructures under an external magnetic field, by carefully controlling the thickness of the stabilizing reagent on the surfaces of the ferrite particles. [15] Athanassiou et al used a combination of magnetic fields and atmosphere pressure reducing flame to explore the possibility for preparing metallic nanowires at high production rates.…”