Structural, magnetic, and microwave absorption properties of Mg–Ti–Zr–Co-substituted barium hexaferrites nanoparticles synthesized via sol–gel auto-combustion method

Abstract

The thermal, structural, magnetic, and microwave absorption properties of Ti–Co–Mg–Zr-substituted barium hexaferrite have been investigated for different concentration of dopants. The thermogravimetric analysis has been used to consider the thermal properties of the samples, and we have observed a three-stage degradation process in the thermal decomposition of the as prepared sample. The results of X-ray diffraction studies confirmed the formation of M-type hexaferrite crystal structure. The nature of chemical bonds as well as the structural properties of the samples have been investigated by the fourier transform infrared spectroscopy. The morphology of the samples have been considered using field emission scanning electron microscopy. The effect of substitution of Ti, Co, Mg, and Zr on the magnetic properties of the nanoparticles has been investigated by the vibrating sample magnetometer. Vector network analyzer was also employed to consider the microwave absorption properties of the samples. The reasons of the changes in the magnetic and microwave absorption properties by adding the impurities were also investigated. It was found that the samples with lower concentration of dopants could be used in magnetic recording media, and the ones with higher concentration of dopants are appropriate candidates for microwave absorbers. The reflection loss diagrams of BaMg x Co x Ti x Zr x Fe12−4x O19 for (a) x = 0.0, (b) x = 0.1, (c) x = 0.2, (d) x = 0.3, (e) x = 0.4, and (f) x = 0.5. The samples with higher concentration of dopants are appropriate candidates for microwave absorbers.