Excellent Microwave Absorbing Properties of Nd3+‐Doped Ni–Zn Ferrite/PANI Nanocomposite for Ku Band

Nd3+‐substituted Ni–Zn ferrite nanoparticles are synthesized by the sol–gel autocombustion technique, and their nanocomposite with polyaniline (PANI) is prepared by in situ polymerization. X‐ray diffraction patterns confirm the formation of single‐phase cubic spinel structure of the prepared ferrite samples. The crystallite size of the synthesized ferrite nanoparticles is found to be in the range of 16−52 nm. The saturation magnetization is observed to decrease due to nonmagnetic polyaniline coating on ferrite nanoparticles. The microwave absorbing properties of ferrite nanoparticles and ferrite/polyaniline nanocomposite are investigated using vector network analyzer in the frequency range of 2−18 GHz for different sample thickness. The minimum value of reflection loss is found to be −6.0 dB at a frequency of 13.20 GHz for Ni0.5Zn0.5Fe1.9Nd0.1O4 ferrite nanoparticles of thickness 2.0 mm, and −53.72 dB at a frequency of 14.48 GHz for Ni0.5 Zn0.5Fe1.9Nd0.1O4/PANI nanocomposite of sample thickness 1.7 mm. The prepared nanocomposite absorbs 99.99% of the incident microwave at a frequency of 14.48 GHz. The microwave absorbing properties improve with a shift of absorption frequency toward higher level for the nanocomposite sample. Herein, Ni0.5Zn0.5Fe1.9Nd0.1O4 ferrite nanoparticles and core–shell Ni0.5Zn0.5Fe1.9Nd0.1O4/polyaniline nanocomposite synthesized by gel thermal decomposition method (with lemon juice as a biofuel) and chemical polymerization method, respectively, are reported. The nanocomposite shows better reflection loss of ‐53.72 dB at Ku band frequency comparing to the individual forms of ferrite and polyaniline.