Alteration in Structural, Spectral, Magnetic and Dielectric Properties of Cobalt Ferrite NPs through Manganese Substitution

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Investigations into the effects of manganese substitution on the properties of cobalt ferrite nanoparticles have led to a new understanding of their potential as electromagnetic interference (EMI) shielding materials. The researchers, from the College of Basic Sciences and Humanities, synthesized MnxCo1-xFe2O4 nanoparticles using a simple and cost-effective sol-gel auto-combustion technique. The team analyzed the structural, elastic, spectral, magnetic, and dielectric properties of the nanoparticles, finding significant changes in their behavior with increasing manganese substitution.

Key Takeaways:

  • The researchers synthesized MnxCo1-xFe2O4 nanoparticles with varying levels of manganese substitution, ranging from x = 0.00 to 1.00, and investigated their structural, elastic, spectral, magnetic, and dielectric properties.
  • The nanoparticles were annealed at 400°C and analyzed using X-ray diffraction, revealing that they were crystallized in a mixed cubic spinel phase, with crystallite sizes ranging from 20.0 to 29.1 nm and lattice constants between 8.361 and 8.38 Å.
  • The elastic parameter was calculated through Rietveld refinement, and the 'Law of Approach to Saturation' was used to determine the saturation magnetization (MS) and cubic anisotropy constant (K1).
  • The value of MS decreased from 66.29 emu/g (x = 0.00) to 51.60 emu/g (x = 1.00) with increasing manganese substitution.
  • The dielectric constant was fitted with a modified Debye's function, indicating more than one ion contributing to the dielectric relaxation.
  • The x = 0.75 composition exhibited minimum dielectric loss, maximum AC conductivity, and moderate magnetic and dielectric responses, making it the optimal candidate for EMI shielding applications.

Statistics:

  • The crystallite sizes of the MnxCo1-xFe2O4 nanoparticles ranged from 20.0 to 29.1 nm.
  • The lattice constants of the nanoparticles were between 8.361 and 8.38 Å.
  • The saturation magnetization (MS) decreased from 66.29 emu/g (x = 0.00) to 51.60 emu/g (x = 1.00).
  • The dielectric constant was fitted with a modified Debye's function in the frequency range of 100 Hz-120 MHz.
  • The calculated values of spread factor and relaxation time were between 0.6230 and 0.7266 and 35.7 x 10-4-11.4 x 10-4 s, respectively.

Sources:

  • Alteration In Structural, Spectral, Magnetic and Dielectric Properties of Cobalt Ferrite Nps Through Manganese Substitution. Ceramics International, 2025;51(21):34175-34194.
  • College of Basic Sciences and Humanities, Department of Physics, G. B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India.
  • University Grants Commission, India.