Formation, Characterization, and Magnetic Properties of Fe₃O₄ Nanowires Encapsulated in Carbon Microtubes

Abstract

Iron oxide (Fe3O4) nanowires encapsulated in carbon microtubes (defined as “CIOs”) with a diameter range of 150−1500 nm, and lengths up to 6 um were obtained by pyrolyzing an ethanol/ferrocene mixture in an autoclave at 600 °C. The inner Fe3O4 nanowires (defined as “IOs”) are single crystalline with a diameter range of 55−750 nm. Magnetic hysteresis loop measurements show that the CIOs display ferromagnetic properties at room temperature. In addition, carbon microtubes (CMTs) were obtained after the inside IOs were dissolved by aqueous HCl acid.

Self‐Assembly and Embedding of Nanoparticles by In Situ Reduced Graphene for Preparation of a 3D Graphene/Nanoparticle Aerogel

“…As shown in Figure 2 e, the material is superparamagnetic, with a saturation magnetization M s = 3.4 emu g − 1 . The value is near to the previously reported Fe 3 O4/C nanowires (5.11 emu g − 1 ), [ 35 ] indicating that the existence of graphene decreases the saturation magnetization of Fe 3 O 4 nanoparticles. In addition, the superparamagnetic behavior of the product reveals that the Fe 3 O 4 particles still have sizes on the nanometer scale.…”

Facile fabrication of long α-Fe2O3, α-Fe and γ-Fe2O3 hollow fibers using sol–gel combined co-electrospinning technology

“…8a) and γ -Fe 2 O 3 (Fig. 8c) hollow fibers show ferromagnetic behavior [26]. The magnetization (M s ), remanent magnetization (M r ), and coercivity (H c ) of α-Fe hollow fibers are respectively 130.2 emu g −1 , 45.6 emu g −1 , and 472.2 Oe.…”

Synthesis, characterization, and comparative gas-sensing properties of Fe2O3 prepared from Fe3O4 and Fe3O4-chitosan

“…The XRD pattern indicates that all the peaks could be perfectly indexed to a pure rhombohedral crystalline phase of ␣- observed for the two samples, suggesting that Fe 3 O 4 NPs have superparamagnetic properties. This observation can be ascribed to the small size of NPs, which is less than the superparamagnetic critical size (25 nm) [15]. The saturation magnetization of pristine Fe 3 O 4 NPs was relatively high (76.68 emu/g), indicating good crystal structure.…”

“…For biomedical applications, Fe 3 O 4 NPs are often treated with surface modification in order to increase their chemical stability and improve their biocompatibility. A variety of materials have been investigated for the modification of Fe 3 O 4 NPs: precious metals [13], silica [14], carbon [15], biopolymers [16][17][18], and CS. Among these materials, CS is a partially acetylated glucosamine biopolymer with many useful features such as hydrophilicity, biocompatibility, and biodegradability.…”