Structural and magnetic properties of nb-zn doped barium strontium hexaferrite nanocomposite powder prepared by sol-gel method

M-type hexagonal ferrites with chemical composition Ba0.5Sr0.5Fe12-2xNbxZnxO19(X=0, 0.05, 0.1, 0.25, 0.5 mol %) have been synthesized by sol-gel method using D- glucose as fuel. In the present work, Barium, Strontium, Iron, Zinc nitrate, Niobium chloride are used raw materials and D-glucose was used as fuel. The prepared samples were calcined at 8000C and 9500C. TGA/DTA curve shows there is no weight loss above 8500C which confirmed the formation of barium strontium hexaferrite. FTIR spectra exhibit the band in the range of 453– 495cm-1 which revealed the presence of hexagonal ferrite. The phase formations were investigated by X-ray diffraction. X-ray powder analysis confirmed the formation of hexagonal magnetoplumbite structure. The average particle size of the sample is in the range of 31- 48 nm. SEM micrographs showed the powder is well crystallized and the particles are hexagonal structure with needle shape and platelet form. EDAX analysis showed the evidence for the presence of Ba, Sr, Fe, Nb and Zn. The VSM measurement revealed that the doping of Nb-Zn ions caused the change in the magnetic properties such as coercivity, saturation magnetization and remanence magnetization. The improving saturation magnetization and remanence magnetization and reducing coercivity were favorable for high density perpendicular magnetic recording applications.