Microwave absorption properties of SiCN ceramics doped with cobalt nanoparticles

Polymer-Derived Si-Based Ceramics: Recent Developments and Perspectives

“…There are normally various ways of doping. The most commonly used route is to uniformly mix the uncrosslinked or the crosslinked precursor polymer with the dopants directly by magnetic stirring, ultrasonic dispersion, or ball milling [8,14,27,28,41,44,45]. For example, Guo's group [14] used an inorganic metal salt as a metal source and directly mixed it with a precursor polymer to prepare a metal-doped polymer-derived SiOC composite material, in which the electrical conductivity of Cu-doped SiOC ceramic was 9.32 × 10 −2 S•cm −1 .…”

“…An excellent electromagnetic wave absorbing material should meet the following requirements [55]: (i) strong absorption capacity and impedance matching characteristics, which means small reflection coefficient (RC min ); (ii) wide effective absorption bandwidth (EAB, RC min is less than the corresponding frequency range of −10 dB); (iii) low density and high temperature stability; (iv) good mechanical properties. Among all electromagnetic wave absorbing materials, PDCs have attracted increasing attention due to their controllable microstructure, lightweight, outstanding mechanical properties, and wide absorption [19,27,28,30,32,44,45,82] features.…”

“…Therefore, the shapes of polymers could be tailored according to specific requirements after pyrolysis. At present, the most widely studied PDCs systems are mainly PDCs-SiC [5][6][7][8][9][10][11][12], PDCs-SiOC [13][14][15][16][17][18][19][20][21][22], and PDCs-SiCN [23][24][25][26][27][28][29][30][31][32] systems.…”

“…It is detrimental to the mechanical properties of ceramics, but this feature can be used to prepare ceramics with hierarchical porous structure and high specific surface area [7,8,12,30,48]. Meanwhile, introducing suitable additives to the preceramic polymers in the form of particles or the chemical precursors can enable PDCs with additional functions, such as catalysis [7,18,49,50], electromagnetic wave absorption [19,27,28,30,32,45,[51][52][53][54][55], filtration [8,9,11,56,57], and electrochemical energy storage [48,[58][59][60]. Su's group [48] used graphene-modified PDCs-SiOC fibers to fabricate flexible ceramic cloths with hierarchical porous structure and rough surface by spinning, which can be used for high performance lithium storage application.…”

Fabrication of (SiC-AlN)/ZrB2 Composite with Nano-Micron Hybrid Microstructure via PCS-Derived Ceramics Route

“…PDCs are mainly composed of a network by free carbon and Si-rich nanodomains inside [ 9 ], while grains of PDCs are usually nanosized. This unique microstructure renders excellent physical and chemical properties in PDCs [ 10 , 11 ], such as thermal [ 12 , 13 , 14 , 15 ], electrical [ 16 , 17 , 18 ], electrochemical energy storage [ 19 , 20 ], and electromagnetic properties [ 21 , 22 , 23 , 24 , 25 ]. Nevertheless, during the pyrolysis of the ceramic precursors, a large amount of small molecule gas would be released, and the green body would shrink, with the formation of pores and cracks.…”