Influence of Sm on the Structural, Magnetic and Microwave Properties of SrFe12O19

Abstract

The fascinating influence of Sm substitution on the structural, magnetic and microwave properties of strontium hexaferrite is studied explicitly. The desired samples, Sr1-xSmxFe12O19 (x = 0, 0.025 and 0.05) are prepared using ethylene glycol and citric acid assisted sol-gel auto-combustion method. Different characterization techniques such as XRD, SEM, magnetic, XPS and microwave measurements are adopted to analyze the various physical properties due to substitutions. Rietveld refinement of XRD data confirms that, the prepared samples crystallize in hexagonal structure belonging to P63/mmc space group. SEM analysis indicates that the average grain size decreases after substitutions. Temperature dependent magnetization exhibits a peculiar Hopkinson peak . M-H isotherms show the characteristics hysteresis loops, resembles to that of hard ferrites. Furthermore, with substitutions, saturation magnetization (Ms) decreases and coercivity (Hc) increases as compared to the parent one. The presence of all the elements in the system as well as their oxidation states are analyzed through XPS. The room temperature microwave properties of the synthesized sample in Ka band frequency range (27-40 GHz) is measured. From the reflection loss analysis, the typical EM absorption of all the samples lies above 99%, which shows that these hexaferrites can be used as suitable candidates for electromagnetic shielding applications.