A Study of the Morlogical Properties of SrFe12-xCoxO19 (x=0, 0.1, 0.2) Hexaferrite Nanoparticles

In this work, a series of M-type strontium hexaferrite samples having nominal composition SrFe12-xCoxO19 (x = 0.0, 0.1 and 0.2) with different morphologies have been synthesized by sol-gel method The decomposition behavior and mechanism of phase formation of SrFe12O19 were investigated using of thermogravimetric analysis (DTA/TGA). The crystal structure and morphology of samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The XRD results showed that all of the samples have the major phase of SrFe12O19 with M-type hexaferrite structure, and the Co-doped samples also have the minor phases of Fe2O3 and K2Fe10O16. It seems that the Fe3+ ions are substituted by Co2+ ions in the crystallography sites of the SrFe12O19 structure. The average crystallites size is found in the range of 16-39 nm, which is small enough to obtain a suitable signal-to-noise ratio in high-density recording media. The morphology and average particles size of samples were determined by SEM. In the Fourier transform infrared spectrometry (FT-IR) spectra of all the samples, three peaks were observed. All of these peaks correspond to the metal-oxygen stretching in hexaferrites.