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<p>Yttrium-substituted Co<sub>0.5</sub>Cu<sub>0.5</sub>Y<sub>x</sub>Fe<sub>2-x</sub>O<sub>4</sub> ferrites (x = 0.00, 0.03, 0.06, 0.09) were synthesized via conventional solid-state route and sintered at 800&#xa0;°C to explore their structural, optical, and magneto-dielectric characteristics. X-ray diffraction confirmed a predominant cubic spinel phase, with orthoferrite secondary phases appearing at higher Y contents. The lattice parameter initially expanded to 8.376 Å (x = 0.03) but decreased systematically to 8.356 Å, lower than the undoped value (8.362 Å) at x = 0.09. SEM revealed well-crystallized grains with reduced grain size from 180.25&#xa0;μm to 108.76&#xa0;μm, corroborated by EDS showing stoichiometric composition. Optical studies indicated a widening band gap from 3,80&#xa0;eV to 5.05&#xa0;eV with Y incorporation. Dielectric measurements showed a significant drop in dielectric constant (1305.01 → 183.41) and loss tangent (2.22 → 1.24) with doping and frequency, consistent with interfacial polarization. Electric modulus analysis revealed an increased Mɛ′ value (0.044 at x = 0.09) and relaxation peaks in Mɛ″ shifting from 3.28&#xa0;kHz to 11&#xa0;kHz, indicating grain boundary relaxation. Nyquist impedance spectra exhibited dual arcs associated with grain (Mɛ″ ≈ 0.008 at x = 0.09) and grain boundary (Mɛ″ ≈ 0.0045 at x = 0.09) contributions. Magnetic characterization showed imaginary permeability ranging from 2479.8 to 3022 and energy loss factors between 298 and 340 at low frequencies, both declining rapidly beyond ~ 3&#xa0;kHz. Compressed magnetic Nyquist arcs with increasing Y confirmed enhanced AC conductivity, with x = 0.09 delivering the smallest arc and superior performance. Notably, this composition achieved impedance matching of ~ 0.68 at 0.6&#xa0;MHz, indicating promising electromagnetic behavior in the MHz range, with potential applicability in high-frequency devices pending further investigation in the GHz regime.</p>

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Development of Y-Doped Co-Cu Ferrites with enhanced magneto-dielectric properties for high-frequency antennas

  • 期刊论文

  • 发表日期：

    2026年5月2日

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  • Mehedi Hasan,
  • Md. Alamgir Hossain,
  • Md. Khorshed Alam,
  • Sadik Mahmud,
  • Shohanur Rahman Sagor,
  • Md. Asaduzzaman

摘要

Yttrium-substituted Co0.5Cu0.5YxFe2-xO4 ferrites (x = 0.00, 0.03, 0.06, 0.09) were synthesized via conventional solid-state route and sintered at 800 °C to explore their structural, optical, and magneto-dielectric characteristics. X-ray diffraction confirmed a predominant cubic spinel phase, with orthoferrite secondary phases appearing at higher Y contents. The lattice parameter initially expanded to 8.376 Å (x = 0.03) but decreased systematically to 8.356 Å, lower than the undoped value (8.362 Å) at x = 0.09. SEM revealed well-crystallized grains with reduced grain size from 180.25 μm to 108.76 μm, corroborated by EDS showing stoichiometric composition. Optical studies indicated a widening band gap from 3,80 eV to 5.05 eV with Y incorporation. Dielectric measurements showed a significant drop in dielectric constant (1305.01 → 183.41) and loss tangent (2.22 → 1.24) with doping and frequency, consistent with interfacial polarization. Electric modulus analysis revealed an increased Mɛ′ value (0.044 at x = 0.09) and relaxation peaks in Mɛ″ shifting from 3.28 kHz to 11 kHz, indicating grain boundary relaxation. Nyquist impedance spectra exhibited dual arcs associated with grain (Mɛ″ ≈ 0.008 at x = 0.09) and grain boundary (Mɛ″ ≈ 0.0045 at x = 0.09) contributions. Magnetic characterization showed imaginary permeability ranging from 2479.8 to 3022 and energy loss factors between 298 and 340 at low frequencies, both declining rapidly beyond ~ 3 kHz. Compressed magnetic Nyquist arcs with increasing Y confirmed enhanced AC conductivity, with x = 0.09 delivering the smallest arc and superior performance. Notably, this composition achieved impedance matching of ~ 0.68 at 0.6 MHz, indicating promising electromagnetic behavior in the MHz range, with potential applicability in high-frequency devices pending further investigation in the GHz regime.