Combustion-Synthesized Ni–Cd Ferrites and their Structural, Magnetic, and Microwave Absorbing Properties

Ni1 – xCdxFe2O4 ferrites (x = 0.2, 0.4, 0.6) were prepared by solution-combustion synthesis and characterized by XRD, SEM, FTIR spectra, hysteresis measurements, and voltage standing wave ratio (VSWR). The ferrite particles had a size of 20–30 nm. The saturation magnetization observed for x = 0.6 composition was about 56 emu/g. The real and complex permittivity in the frequency range 8–12 GHz was found to vary between 10 and 30. The Cd content of ferrites was found to increase the MW absorption. At x = 0.6, the MW absorbance attained a value of 0.958 at f = 9.5 GHz.