Structural and magnetic properties of Sr۲Co۱.۵Mg۰.۳Fe۱۱.۲Zr۰.۴Cd۰.۴O۲۲hexaferrite synthesized by sol-gel auto-combustion method

The type hexagonal ferrite samples of a chemical formula Sr۲Co۱.۵Mg۰.۳Fe۱۱.۸Zr۰.۴Cd۰.۴O۲۲ weresynthesized via wet chemical sol–gel auto-combustion method. The X-ray diffraction (XRD)patterns confirm single phase Y-type hexagonal ferrite and various parameters such as latticeconstants and cell volume have been calculated from XRD data. The Fourier transform infrared(FTIR) spectra show the characteristics absorption ferrite peaks of the sintered sample. Themicrostructure was studied by field emission scanning electron microscopy (FESEM). All theferrites show a hexagonal platelet-like shape which is a most suitable shape for microwaveabsorption. The results revealed that single Co۲Y hexaferrite phase was obtained at relatively lowtemperature ۱۰۵۰ °C for ۳h compare with common solid state reaction. Magnetic properties of thesamples were also studied as a function of heat treatment temperature and it showed largesaturation magnetization (Ms) ranging from ۳۲.۶۵ to ۴۲.۰۰ emu/g and coercivity decrease from۹۱۰ to ۶۳۷ Oe depending on the heat treatment temperature. The very weak saturationmagnetization at relatively lower temperature (say ۱۰۰۰ °C) is due to the presence of someimpurities, such as SrO and Fe۲O۳. The saturation magnetization increases with increasing heattreatment temperature above ۱۰۵۰ °C, while the coercivity showed a reversed order.

Keywords:

sol-gel auto-combustion , nano particle , phase formation , Y-type hexaferrite.