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<p>Designing meta-absorbers in the high-frequency range with improved absorption and dissipation remains difficult. Electromagnetic pollution from increased high-frequency radiation emitted by electronic devices significantly affects humans and other living beings. Key to addressing these issues is the synthesis of ferrite and the development of related meta-absorbers. Nd<sup>3+</sup>-doped Sr<sub>2</sub>Co<sub>2</sub> Y-type hexagonal ferrites (YHFs) with the composition Sr<sub>2</sub>Co<sub>2</sub>Fe<sub>12−x</sub>Nd<sub>x</sub>O<sub>22</sub>, where 0.0 ≤ x ≤ 0.075, were prepared via the sol–gel auto-combustion method. The effects of Nd<sup>3+</sup> doping on structural, spectral, and dielectric properties were thoroughly investigated. Characterisation was performed using XRD, FTIR, Raman, and UV–Vis spectroscopy. Dielectric properties of the Nd<sup>3+</sup>-doped ferrites were examined to assess charge carrier mobility across different frequencies. XRD confirmed the presence of the Y phase in the samples, with lattice parameters' a from 5.871 to 5.900&#xa0;Å and ‘c’ from 111.76 to 112.23&#xa0;Å, indicating lattice stretching. Crystallite sizes ranged from 16.40 to 20.19&#xa0;nm. FTIR spectra showed absorption bands between 4000 and 500&#xa0;cm<sup>−1</sup>. UV–Vis analysis revealed enhanced absorption due to Nd<sup>3+</sup> doping. Raman spectra displayed multiple broad peaks. Dielectric parameters such as ε', ε'', a, c, tanδ, M', and M'' were measured at room temperature across 1 to 6&#xa0;GHz. Changes in dielectric behaviour were explained using the Maxwell–Wagner model. Cole–Cole plots indicated that Nd<sup>3+</sup> substitution significantly affects magnetic relaxation dynamics, demonstrated by variations in impedance responses. The sample with x = 0.050 achieved reflection-loss maxima of − 42.11&#xa0;dB at 1.38&#xa0;GHz and − 58.10&#xa0;dB at 3.21&#xa0;GHz. TE mode absorption was enhanced by Nd doping, although absorption decreased with increasing incidence angle from 0 to 60 degrees. These excellent dielectric properties, along with additional characterisation, support their use for microwave attenuation.</p>

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Unveiling the absorptivity, physicochemical, and dielectric charge mobility of Nd3+-doped Sr2Co2 YHFs-designed meta-absorbers for C-band absorption applications

  • 期刊论文

  • 发表日期：

    2026年3月28日

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  • Uzma Tanveer,
  • Majid Niaz Akhtar,
  • Asif Jamil,
  • Marcus Vinicius Castegnaro,
  • Shagufta Gulbadan,
  • Maira Younas,
  • Imran Shakir,
  • Zainab Mufarreh Elqahtani,
  • Sami Ullah,
  • Muhammad Azhar Khan,
  • M. S. Al-Buriahi

摘要

Designing meta-absorbers in the high-frequency range with improved absorption and dissipation remains difficult. Electromagnetic pollution from increased high-frequency radiation emitted by electronic devices significantly affects humans and other living beings. Key to addressing these issues is the synthesis of ferrite and the development of related meta-absorbers. Nd3+-doped Sr2Co2 Y-type hexagonal ferrites (YHFs) with the composition Sr2Co2Fe12−xNdxO22, where 0.0 ≤ x ≤ 0.075, were prepared via the sol–gel auto-combustion method. The effects of Nd3+ doping on structural, spectral, and dielectric properties were thoroughly investigated. Characterisation was performed using XRD, FTIR, Raman, and UV–Vis spectroscopy. Dielectric properties of the Nd3+-doped ferrites were examined to assess charge carrier mobility across different frequencies. XRD confirmed the presence of the Y phase in the samples, with lattice parameters' a from 5.871 to 5.900 Å and ‘c’ from 111.76 to 112.23 Å, indicating lattice stretching. Crystallite sizes ranged from 16.40 to 20.19 nm. FTIR spectra showed absorption bands between 4000 and 500 cm−1. UV–Vis analysis revealed enhanced absorption due to Nd3+ doping. Raman spectra displayed multiple broad peaks. Dielectric parameters such as ε', ε'', a, c, tanδ, M', and M'' were measured at room temperature across 1 to 6 GHz. Changes in dielectric behaviour were explained using the Maxwell–Wagner model. Cole–Cole plots indicated that Nd3+ substitution significantly affects magnetic relaxation dynamics, demonstrated by variations in impedance responses. The sample with x = 0.050 achieved reflection-loss maxima of − 42.11 dB at 1.38 GHz and − 58.10 dB at 3.21 GHz. TE mode absorption was enhanced by Nd doping, although absorption decreased with increasing incidence angle from 0 to 60 degrees. These excellent dielectric properties, along with additional characterisation, support their use for microwave attenuation.