Structure and Magnetic Properties of Ti-Co Co-Cubstituted Barium Hexaferrite

Polycrystalline Ti-Co co-substituted M-type ferrites Ba (TiCo)xFe12-2xO19 (x=0.25,0.5, 0.75, 1.0 ) samples were prepared by the citrate precursor method. The particle structure and morphology of the products were characterized by X-ray powder diffraction (XRD) and Field Emission Scanning Electron Microscope (FE-SEM). The effects of the substitution rate on the magnetic properties of samples were analysed by magnetic measurement with the Vibrating Sample Magnetometer (VSM) of Physical Properties Measurement System (PPMS). The XRD patterns show that only one type of crystalline phase can be detected and the substitution did not change the crystal structure. The SEM micrographs of Ba (TiCo)xFe12-2xO19 calcined at 450 °C for 5h, and then 950°C for 5h show that the M-type ferrite particles were homogeneously shaped and the grain sizes had no obvious differences when the substitution rate changed. The magnetic hysteresis loops illustrate that the coercivity (Hc) decreased rapidly with the increasing of Ti-Co substitution, while the saturation magnetization (Ms) changed slowly.