Influence of pH Adjustment Parameter for Sol–Gel Modification on Structural, Microstructure, and Magnetic Properties of Nanocrystalline Strontium Ferrite

Synthesis of nanocrystalline strontium ferrite (SrFe(12)O(19)) via sol–gel is sensitive to its modification parameters. Therefore, in this study, an attempt of regulating the pH as a sol–gel modification parameter during preparation of SrFe(12)O(19) nanoparticles sintered at a low sintering temperature of 900 °C has been presented. The relationship of varying pH (pH 0 to 8) on structural, microstructures, and magnetic behaviors of SrFe(12)O(19) nanoparticles were characterized by X-ray diffraction (XRD), field emission scanning microscope (FESEM), and vibrating sample magnetometer (VSM). Varying the pH of precursor exhibited a strong effect on the sintered density, crystal structure and magnetic properties of the SrFe(12)O(19) nanoparticles. As the pH is 0, the SrFe(12)O(19) produced relatively largest density, saturation magnetization, M(s), and coercivity, H(c), at a low sintering temperature of 900 °C. The grain size of SrFe(12)O(19) is obtained in the range of 73.6 to 133.3 nm. The porosity of the sample affected the density and the magnetic properties of the SrFe(12)O(19) ferrite. It is suggested that the low-temperature sintered SrFe(12)O(19) at pH 0 displayed M(s) of 44.19 emu/g and H(c) of 6403.6 Oe, possessing a significant potential for applying in low-temperature co-fired ceramic permanent magnet.