Multiwalled carbon nanotubes–BaTiO3/silica composites with high complex permittivity and improved electromagnetic interference shielding at elevated temperature

Effect of feedstock characteristics on the dielectric and microwave absorption properties of plasma sprayed NiCrAlY/Al2O3 coatings

“…As we all known, the conductive NiCrAlY is dispersed in the insulating Al 2 O 3 matrix to constitute heterogeneous composites [11]. The accumulation of free charge will exist in the insulation/conductor interface, which forms interfacial polarization.…”

Dependences of microstructure on electromagnetic interference shielding properties of nano-layered Ti3AlC2 ceramics

“…Compared to traditional metal- and carbon-based EMI shielding materials, ceramic composites exhibit the great advantage of being mechanically stiff and thermo-stable, which could guarantee their functionality at harsh environments 6 . Besides, the relatively high permittivity and dielectric loss of ceramics are favourable for the attenuation of EMI waves 4,5,7–9 . Nevertheless, the commonly inferior electrical conductivity becomes a major obstacle to obtain high EMI shielding effectiveness (SE) in ceramics.…”

“…Nevertheless, the commonly inferior electrical conductivity becomes a major obstacle to obtain high EMI shielding effectiveness (SE) in ceramics. Although the electrical conductivity and EMI SE of ceramics could be both significantly enhanced by incorporating highly conductive carbon materials such as carbon nanotubes (CNTs) 4,10 , carbon fibers (C f ) 6,11 , graphene nanoplatelets (GNPs) 5,7,8,12 , and pyrolytic carbon 13,14 , the incorporation of those carbon nanostructures in ceramic composites is hindered by the difficulty of homogenous dispersion and their poor oxidation resistance at high temperatures. Accordingly, it is of great interest to explore intrinsically conductive ceramics as effective high-temperature EMI shielding materials.…”

Crystallization Mechanism of CVD Si3N4–SiCN Composite Ceramics Annealed in N2 Atmosphere and Their Excellent EMW Absorption Properties

“…There are two kinds of microwave absorbents, one is electric loss materials, such as conducting polymers and carbon materials, and the other is magnetic loss materials, such as composites including ferrite, nickel, and zinc. [4][5][6] However, neither the traditional electric loss materials nor the magnetic loss materials can meet all the requirements of high-temperature electromagnetic-absorbing properties, because the remarkably high chemical and mechanical stability and superior microwave absorption properties such as thin, lightweight, and wide frequency range are needed. 7,8 Generally, CVD Si-based ceramics exhibit enhanced oxidation resistance, thermal stability, and fracture toughness.…”