SYNTHESIS, STRUCTURE AND ELECTROMAGNETIC PROPERTIES OF NANOCOMPOSITES WITH THREE-COMPONENT FeCoNi NANOPARTICLES

Infrared heating was used to synthesize FeCoNi/C nanocomposites, where nanoparticles of FeCoNi ternary alloy are stabilized and uniformly distributed in the carbon matrix volume. The authors studied the impact of synthesis temperature and percentage ratio of metals upon the structure, composition and electromagnetic properties. X-ray phase analysis and Mossbauer spectroscopy showed that ternary alloy nanoparticles with different compositions and crystalline lattice types can be formed with the rise in synthesis temperature and iron concentration. Resonator method was used to examine frequency dependencies of relative complex dielectric and magnetic permeabilities of nanocomposites in the range of 3-12 GHz. Calculation of reflection coefficient based on experimental permeability data showed that by varying synthesis temperature and percentage ratio of metals one can control the frequency range of effective absorption of electromagnetic waves. It was established that increase in relative iron content from 33 to 50 rel.% leads to the shift of minimal electromagnetic wave reflection coefficient band from f similar to 12+ GHz to frequency f similar to 6 GHz at identical absorber thickness.