Effect of rare earth doping on the electromagnetic response of hard ferrites SrFe12O19 for potential application in high-frequency devices

Abstract

This work explores the synthesis, characterization, and potential application of rare earth doping on hard ferrites, focusing on their unique electromagnetic properties for potential applications in radio frequency (RF) devices. This study investigates the influence of rare earth (Sm+3) doping on structural and dielectric properties of strontium ferrite. Samarium doped strontium ferrite with composition Sr1-xSmxFe12O19(x=0.0,0.1,0.2,0.3) is prepared using the sol-gel auto combustion technique. The prepared samples' crystal structural and morphological properties were studied using an X-ray diffractometer (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and RAMAN spectroscopy. XRD patterns of rare earth substituted strontium ferrite confirmed the formation of a hexagonal phase together with an impurity phase of Fe2O3 for x=0.3. FTIR analysis establishes metal and Oxygen (M-O) stretching vibrations in Sr1-xSmxFe12O19 due to various interstitial sites in its structure. The Raman result shows the presence of four Raman active modes in prepared powders. Meanwhile, the broadening of Raman peaks with Sm2+ doping is also observed. Electromagnetic properties were obtained in the frequency region 2-18 GHz. An increasing tendency is observed in the real part of permittivity and permeability of all doped samples in the frequency region 2-18GHz. The reflection loss was observed for sample x=0.2 with the maximum value of >-40dB at 18 GHz, and the adequate absorption bandwidth is 10 GHz from 8GHz to above 18GHz. On the basis of these results, among all prepared samples, Sr0.8Sm0.2 Fe12O19 is found to be the most suitable candidate for microwave absorbers.