RADAR absorption study of BaFe12O19/ZnFe2O4/CNTs nanocomposite

Magnetic composite comprising barium hexaferrite and zinc spinel ferrite nanoparticles, BaFe12O19/ZnFe2O4 has been synthesized by auto-combustion method including citrate precursor using the sol-to-gel (S-G) followed by gel-to-nanocrystalline (G-N) conversion. The resulting 'as synthesized' powder is heat treated (HT) at 700 °C for 2 h in air atmosphere. The hysteresis loops show an increase in saturation magnetization from 24.10 to 53.49 emu/g with increasing HT temperatures. The multiwalled carbon nano tubes (CNTs) were synthesized by thermal decomposition of acetylene gas over iron-catalyst coated silicon substrate in the temperature range of 750-800 °C. A RADAR absorbing medium is developed by dispersing CNTs in the magnetic composite of barium and zinc ferrite nanoparticles. Reinforcement of certain mass of CNTs improves the RADAR absorption properties and wave band of BaFe12O19/ZnFe2O4 absorbent. When 20 wt% CNTs is mixed with BaFe12O19/ZnFe2O4 nanoparticles to fabricate a composite with 2 mm thickness, the maximum reflection loss reaches to −43.22 dB at 10.30 GHz and −10 dB bandwidth reaches 2.95 GHz.