Synthesis, characterization and magnetic properties on nanocrystalline BaFe 12O 19 ferrite

Abstract

Single phase BaM (BaFe 12O 19) ferrites are prepared by using sol–gel method. The preparing conditions of samples are investigated in detail, such as acid/nitrate ratio, the value of pH and annealing temperature. The best conditions on preparing BaFe 12O 19, which can be obtained on a Fe/Ba ratio of 12, the citric acid contents R = 3, the starting pH of solution is 9, and annealing temperature 950 °C. The thermal decomposition behavior of the dried gel was examined by TG–DSC, the structure and properties of powders were measured respectively by XRD techniques. The magnetic properties of barium ferrites are emphatically researched about the changing crystallite size and annealing temperature by the vibrating sample magnetometer (VSM). Magnetic measurement shows that the barium ferrite samples annealed at 1000 °C has the maximal coercive field of 5691.91 Oe corresponding to the maximal remnant magnetization of 35.60 emu/g and the sample synthesized at 1000 °C has the maximal saturation magnetization of 60.75 emu/g.