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Structural, magnetic and high frequency (1-6 GHz) parameters of Sr-substituted BaFe2O4 monoferrites synthesized by sol-gel method

Ahmad, M ; Sharif University of Technology | 2019

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  1. Type of Document: Article
  2. DOI: 10.1142/S0217984919502191
  3. Publisher: World Scientific Publishing Co. Pte Ltd , 2019
  4. Abstract:
  5. In this work, Sr-substituted samples of single-phase spinel monoferrites with chemical formula Ba1-xSrxFe2O4 (x = 0.00, 0.33, 0.67, 1.00) were synthesized using sol-gel auto-combustion method. In order to confirm the single-phase formation of these samples, a sample (x = 0.00) was chosen for heat treatment at different temperatures (100, 300, 400, 600 and 700°C) for 4 h. The heat treated sample was then investigated by X-ray diffraction (XRD) analysis and results showed that a single-phase sample can be successfully synthesized at a temperature of 600°C, which is much lower than that reported in earlier literature for synthesis of same structured samples. All the synthesized samples were then sintered at 700°C for 4 h to achieve better crystallinity. From XRD patterns, lattice parameters, cell volume and XRD density as a function of Sr-substitution were calculated. Scanning electron microscopy (SEM) results showed that the grain size increased as the temperature was increased. Fourier transform infrared spectroscopy (FTIR) results confirmed the single-phase spinel monoferrites at 700°C. From M-H loops (x = 0.0, 0.33, 0.67 and 1.00), different magnetic parameters such as saturation magnetization (Ms), remanance (Mr), coercivity (Hc) and magnetic moment (nB) were calculated. Magnetocrystalline anisotropy constant and Y-K angles of Sr-doped Ba monoferrites were also calculated. In addition, the variation of different dielectric parameters (real permittivity, imaginary permittivity, real permeability, imaginary permeability, ac conductivity and loss tangent) as a function of frequency (1-6 GHz) has been discussed in this work. The results suggest that the synthesized materials have many advantages over previously reported single-phase spinel monoferrites. © 2019 World Scientific Publishing Company
  6. Keywords:
  7. Magnetic and electromagnetic measurements ; Sol-gel process ; Spinel ferrites ; Sr-substitution ; Structural analysis
  8. Source: Modern Physics Letters B ; Volume 33, Issue 19 , 2019 ; 02179849 (ISSN)
  9. URL: https://www.worldscientific.com/doi/abs/10.1142/S0217984919502191