The Role of Mn–Mg–Ti–Zr Substitution on Structural and Magnetic Features of BaFe12−x (MnMgTiZr) x/4 O 19 Nanoparticles

Abstract

Substituted barium hexaferrite nanoparticles with composition of BaFe12−x (MnMgTiZr) x/4 O 19 (x = 0–2.5 in a step of x = 0.5) were synthesized by co-precipitation method. The structural, magnetic, and microwave absorption properties of samples were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), vibrating sample magnetometer (VSM), and vector network analysis (VNA). The XRD results show that the magnetoplumbite structures for all samples have been formed. The crystallite size of nanoparticles lies in the range of 26–31 nm. FE-SEM graphs indicated that the particle sizes were almost less than 100 nm and increased with an increase in Mn–Mg–Ti–Zr substitution. The result of hysteresis loops revealed that for x>1, M s decreased with an increase in x content; furthermore, it was found that as the amount of dopant increased from x = 0 to x = 2.5, H c decreased from 4.8 to 0.81 kOe. Based on microwave measurement on reflectivity, doped samples had much more effective reflection loss values than undoped ferrites. It was also found that the maximum reflection loss (−30.1 dB) was achieved by ferrite with the maximum amount of substitution. The obtained results reflected that the proposed composites can be introduced as electromagnetic wave absorption materials.