Study of the structural, magnetic, and microwave absorption properties of the simultaneous substitution of several cations in the barium hexaferrite structure

Abstract

In this research study, multi dopant barium hexaferrites nanoparticles with nominal composition of BaCoxCuxZr2xFe12-4xO19 (x = 0.0, 0.1, 0.2, 0.3, 0.4, and 0.5) have been prepared by sol-gel auto-combustion method. Then, their magnetic and microwave properties were studied in detail. These characteristics were investigated using various instruments including X-ray diffraction (XRD) by the FULLPROF program, Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and vector network analyzer (VNA). The XRD, along with FTIR evaluations confirmed the successful substitution of Co, Cu and Zr cations in the barium hexaferrite lattice. The VSM analysis proved that by increasing cobalt, copper and zirconium substitutions, the saturation magnetization, coercivity and remanence values are decreased. With an increase in the concentration of Co-Cu-Zr ions, a monotonic decrease in coercivity, ranging from 3540 Oe to 396 Oe was also observed. The reasons of the changes in the magnetic and microwave absorption properties by adding the multi dopant were also investigated. The maximum reflection loss of −27.4 dB observed in BaCo0.5Cu0.5ZrFe10O19 sample with a bandwidth of about 5.3 GHz which covered almost whole measured microwave frequency range of 12–18 GHz. Which make it to be a good candidate to design single layer microwave absorber for applying in the Ku band.