Improvement in structural dielectric and magnetic properties of barium hexaferrite nanoparticles by doping zinc ions for microwave absorption application.

Nanotechnology has become visible as one of the most climacteric and expeditiously advancing research areas. Scientific researchers have recently given a demonstration of a keen undivided attention in nanoparticles ferrites. In various technological applications, M-type hexagonal ferrites are one of the most important ferrites used industrially. In this reported research work, sol-gel auto combustion method was used to synthesize Zn substituted barium hexaferrite nanoparticles. A series of varying concentration Ba_1-xZn_xFe₁₂O₁₉ nanoparticles for x= 0.00, 0.20, 0.35 and 0.50 was synthesized. Measurements of Lattice parameters verify structural formation of M-type hexaferrite nanoparticles. Estimation of crystallite sizes of the synthesized nanoparticles was carried out by using Scherr’s relation and it lies in the range of 40-60 nm. The atomic vibration analysis of the Zn substituted M-type hexagonal ferrite nanoparticles was assessed by FTIR investigation. The tetrahedral and octahedral sites were characterized by two absorption bands peak in the FTIR measurements. Vibrating sample magnetometer indicate the rise in the value of saturation magnetization from 37 to 48 emu/g on doping of zinc ions (for x=0.50). All the compositions showed reflection loss in Ku band (12 - 18 GHz) below -10 dB. The value of reflection loss at 15.99 GHz is observed to be maximum which is -19.24 dB for x = 0.50. At the same frequency for maximum reflection loss, the corresponding value of normalized input impedance (Z_in/Z_o) is 0.8 (closer to 1) which demonstrates improved microwave absorption, making synthesized compositions the potential candidate for microwave absorption applications.