Effect of Ti–Zn substitution on structural, magnetic and microwave absorption characteristics of strontium hexaferrite

• Ms, as well as Hc, decreased with substitution of Ti–Zn ions in place of ferric.
• Microwave absorption properties improved with increasing dopant content.
• A composite with x = 2.5 has shown a minimum RL of −36.13 dB at 13.43 GHz.
• A composite with x = 2.5 exhibited the widest bandwidth relative to other composites.

SrFe12−xTix/2Znx/2O19 (x = 0–2.5) powders were synthesized by use of chlorides through co-precipitation method. The obtained powders were then milled by high energy ball mill to crash hard agglomerates and achieve nanoparticles. In order to evaluate microwave absorption versus frequency, composites including ferrite, as a filler, and matrix of polyvinylchloride (PVC) with weight ratio of 70% ferrite were prepared. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), vibrating sample magnetometer (VSM) and vector network analyzer (VNA) were employed to study the structural, magnetic and microwave absorption properties of samples. The XRD patterns showed that the hexagonal single phase were obtained only if x ⩽ 2. FE-SEM micrographs indicated that the particle sizes were almost less than 40 nm. With increasing amount of dopant from x = 0 to x = 2.5, the saturation magnetization and coercivity decreased from 56 emu/g and 1350 Oe to 16 emu/g and 88 Oe, respectively. The maximum loss of electromagnetic waves was −36.13 dB obtained by ferrite with maximum amount of substitution. The obtained results indicated that the proposed composites can be introduced as electromagnetic wave absorption materials.

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