Structural, magnetic and microwave absorption properties of doped Ba-hexaferrite nanoparticles synthesized by co-precipitation method

The structural, magnetic and microwave absorption properties of the barium hexaferrite doped by Zn, Co and Zr cations have been investigated. BaZnxCoxZr2xFe12−4xO19 (x=0.0, 0.1, 0.2, 0.3, 0.4, 0.5) nanoparticles were synthesized by the co-precipitation method in the presence of polyvinyl alcohol (PVA). X-ray diffraction (XRD), thermal analysis (TGA-DTA), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM) and vector network analyzer are employed to investigate the desired properties of the prepared samples. From the XRD evaluation it can be seen that the magnetoplumbite structure for all of the samples have been formed and the average crystallite size of nanoparticles lies in the range of 44±3 nm. The TGA-DTA curves of the undoped sample (x=0.0) indicate that the formation of barium hexaferrite can be obtained at a relatively low temperature of 709 °C. The results of VSM analysis show that the saturation magnetization and coercivity are decreased by increasing the percentage of the dopants. The reflection loss results indicate that the ferrite with the composition of BaZn0.5Co0.5 ZrFe10O19 has appropriate reflection loss (RL<−10 dB) and bandwidth in order to be used as a potential single layer absorber in the frequency range of 8-12 GHz.