Effect of Fe/Pb molar ratio on the structure, magnetic and dielectric properties of PbFe12O19 nanoparticles

In this paper, lead hexaferrite (PbFe12O19) nanoparticles were synthesized by sol-gel method. In order to prepare PbFe12O19 nanoparticles, the metal nitrates with Fe/Pb = 8, 10, 11, 12, 14 ratios and citric acid were used. The structure, morphology, magnetic, and dielectric properties of PbFe12O19 nanoparticles were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), vibrating sample magnetometer (VSM) and LCR meter. XRD results revealed that the samples with Fe/Pb ≤ 10 and Fe/Pb > 10 have single-phase hexaferrite and hematite (α- Fe2O3) structures, respectively. As a result, the sample with Fe/Pb = 10 is single-phase and shows the highest values of the saturation magnetization and remanence magnetization. We found that the values of dielectric constant (ε′) and dielectric loss (ε″) increase with an increase in the Fe/Pb molar ratio from 8 to 12 and then decreases with an increase of Fe/Pb molar ratio to 14. The variation of ac conductivity (σac) with frequency ranging from 1 kHz to 200 kHz showed that electrical conductivity in these ferrites is mainly due to the electron hopping mechanism.