Investigation of Magnetic Properties of γ-Fe2O3 NP-Decorated Carbon Nanostructured Mats

It has been experimentally demonstrated that a carbon nanostructure (CNS)-based structure, called CNS mats, can yield superior magnetic properties. The structure is obtained by decorating CNS with γ-Fe2O3 nanoparticles (NPs) in a three-dimensional (3D) network structure. γ-Fe2O3 NPs are coated on the CNS, resulting in enhanced magnetic properties. The experimental characterization and theoretical analysis reveal that CNS mats decorated with γ-Fe2O3 NPs show superior magnetic properties compared with pristine CNS, as a result of the homogeneous dispersion of γ-Fe2O3 NPs and the highly aligned structure of the CNS. The coercive field (Hc), saturation magnetization (Ms), and remanent magnetization (Mr) were found to be 126 Oe, 22.3 emu/g, and 7.15 emu/g, respectively. In addition, scanning electron microscopy (SEM) and atomic force microscopy (AFM) characterization showed that the carbon nanotubes (CNTs) in each CNS flake within the CNS mat remained well aligned and formed an interconnected 3D network structure. This results in a robust porous structure with high electrical conductivity. Thermogravimetric analysis (TGA) revealed that the presence of the γ-Fe2O3 NPs provides a protective layer for the CNS and results in good thermal stability. The fabricated ultrathin CNS mat offers superior magnetic and electrical performance, making it an attractive candidate for microwave absorption, along with other applications such as electromagnetic shielding, sensors, lithium-ion batteries, and polymer composites.