Electromagnetic Properties of Phosphate Composite Materials with Boron-Containing Carbon Nanotubes

The possibility of developing electromagnetic composite materials based on unfired heat-resistant mechanically strong phosphate ceramics has been studied. Boron-containing multiwalled carbon nanotubes and onion-like particles (B-MWCNTs) synthesized by electric-arc evaporation of a graphite rod enriched with boron are used as a functional additive to the phosphate matrix. According to transmission electron microscopy, the average nanoparticle length is similar to 100 nm. According to X-ray photoelectron spectroscopy and X-ray absorption spectroscopy, the boron content in B-MWCNT walls is less than 1 at %, and substitution of carbon atoms with boron leads to the formation of acceptor states in the conduction band. An increase in the electromagnetic response of phosphate ceramics by similar to 53 and similar to 13-15% for 1.5 wt % B-MWCNT additive is detected in quasi-static and gigahertz ranges, respectively. It is assumed that a stronger effect can be achieved using longer B-MWCNTs than those formed under electric arc conditions.