In this chapter, we will restrict our attention to the ferrites and a few other closely related materials. The great interest in ferrites stems from their unique combination of a spontaneous magnetization and a high electrical resistivity. The observed magnetization results from the difference in the magnetizations of two non-equivalent sub-lattices of the magnetic ions in the crystal structure. Materials of this type should strictly be designated as “ferrimagnetic” and in some respects are more closely related to anti-ferromagnetic substances than they are to ferromagnetics in which the magnetization results from the parallel alignment of all the magnetic moments present. We shall not adhere to this special nomenclature except to emphasize effects, which are due to the existence of the sub-lattices.

Ferromagnetic materials

Two-dimensional MXenes: From morphological to optical, electric, and magnetic properties and applications

Water treatment and environmental remediation applications of two-dimensional metal carbides (MXenes)

Graphene and MXene Nanomaterials: Toward High-Performance Electromagnetic Wave Absorption in Gigahertz Band Range

Recent progress of nanomaterials for microwave absorption

Sandwich-like MXene/Fe3O4 and C/TiO2/α-Fe two-dimensional (2D) nanocomposites were fabricated via in situ hydrothermal assembly of Fe3O4 nanoparticles on MXene nanosheets and postannealing. The as-prepared sandwich-like MXene/Fe3O4 nanocomposites contain uniformly distributed Fe3O4 nanoparticles between the interlayers of the 2D MXene Ti3C2T x nanoflakes. The redox reaction, Ti3C2T x + Fe3O4 → 3TiO2 + 2C + 3Fe, has also been reported for the first time to transform the binary MXene/Fe3O4 nanocomposites into ternary C/TiO2/α-Fe nanocomposites with the 2D structure maintained intact. Such a transition during postannealing gives rise to further enhanced electromagnetic wave absorption compared with that of the MXene/Fe3O4 nanocomposites on top of the already improved performance of the MXene/Fe3O4 compared with that of pristine MXene. The 2D C/TiO2/α-Fe nanocomposites exhibit effective absorption bandwidths of 3.3 and 3.5 GHz at thicknesses of 1 and 1.5 mm, respectively. This work offers a new route for fabricating novel electromagnetic wave absorbers, and the fine balance among lightweight, broad band, and small thickness of the C/TiO2/α-Fe nanocomposites makes them promising in the field of electromagnetic wave absorption.

Self-Assembled Sandwich-like MXene-Derived Nanocomposites for Enhanced Electromagnetic Wave Absorption.

Enhanced magnetic properties of Fe soft magnetic composites by surface oxidation

Developing high-efficiency electromagnetic (EM) wave absorbing materials with light weight, thin thickness, and wide absorption bandwidth is highly desirable for ever-developing electronic and telecommunication devices. Herein, hierarchical metal-organic framework (MOF)-derived Co/C@V2 O3 hollow spheres were designed and synthesized through a facile hydrothermal, precipitation, and pyrolysis method. The composite exhibits both excellent impedance matching and light weight due to the rational combination of hollow V2 O3 spheres and porous Co/C. Additionally, multiple components enable a large dielectric and magnetic loss of the composite, giving rise to enhanced EM wave absorption performance with a maximum reflection loss (RL) of -40.1 dB and a broad effective absorption bandwidth (RL < -10 dB) of 4.64 GHz at a small thickness of 1.5 mm. This work provides insights into the design of hierarchical hollow and porous composites as thin and lightweight EM wave absorbers with efficient absorption, which can also be extended to energy storage, catalysis, and sensing.

Metal-Organic Framework Derived Hierarchical Co/C@V2O3 Hollow Spheres as a Thin, Lightweight, and High-Efficiency Electromagnetic Wave Absorber

A versatile strategy towards magnetic/dielectric porous heterostructure with confinement effect for lightweight and broadband electromagnetic wave absorption

Advanced electromagnetic (EM) wave absorbing materials are technologically important with extensively increasing utilization of EM waves in the gigahertz range Hierarchical structure containing Fe

Chen Wu

Papers

Self-Assembled Sandwich-like MXene-Derived Nanocomposites for Enhanced Electromagnetic Wave Absorption.

Enhanced magnetic properties of Fe soft magnetic composites by surface oxidation

Metal-Organic Framework Derived Hierarchical Co/C@V2O3 Hollow Spheres as a Thin, Lightweight, and High-Efficiency Electromagnetic Wave Absorber

A versatile strategy towards magnetic/dielectric porous heterostructure with confinement effect for lightweight and broadband electromagnetic wave absorption

Hierarchical FeCo@MoS2 Nanoflowers with Strong Electromagnetic Wave Absorption and Broad Bandwidth