Effect of multi dopant barium hexaferrite nanoparticles on the structural, magnetic, and X-Ku bands microwave absorption properties

A co-precipitation method was employed to prepare M-type barium hexaferrite nanoparticles (BaCuxMgxZr2xFe12−4xO19) with different substitutions (x = 0.0, 0.1, 0.2, 0.3, 0.4, and 0.5). Then, their structural, magnetic and microwave properties were reported. These characteristics were investigated using various instruments including thermal analysis (TGA/DSC), X-ray diffraction (XRD) by the FULLPROF program, field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and vector network analyzer (VNA). In accordance with the FESEM graphs, the average particle sizes become smaller as the amounts of dopants increase. The VSM analysis proved that by increasing copper, magnesium and zirconium substitutions, the saturation magnetization, coercivity and remanence values are decreased. With an increase in the concentration of CuMgZr ions, a monotonic decrease in coercivity, ranging from 4420.2 G to 161.64 G, was also observed. By increasing dopant ions from x = 0.0 to x = 0.5, the Curie temperature decreases from 467.2 °C to 230.46 °C. The relationship between reflection loss and frequency was evaluated theoretically for different thickness levels. Also, the resonance frequency shifts to lower frequencies by increasing CuMgZr dopants due to the reduction of anisotropy field. According to microwave properties, BaCu0.5Mg0.5ZrFe10O19 sample could be counted as a single layer attenuator materials candidate for microwaves applications in the 2-18 GHz frequency range.