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Impedance spectroscopy insights into (NiO)(_0.5)/(Fe₂O₃)(_0.5)@C@MoS₂ nanofibers composite for tunable EMI shielding applications

U. Anwar^a, N. A. Noor^b, S. Mumtaz^c,*, I. M. Moussad¹

a Institute of Chemical Sciences, Bahauddin Zakariya University, Multan 60000, Pakistan
b Department of Physics, University of Sargodha, 40100, Sargodha, Pakistan
c Department of Chemical and Biological Engineering, Gachon University, 1342 Seongnamdaero, Sujeong-gu, Seongnam-si 13120, Republic of Korea
d Department of Botany and Microbiology, College of Science, King Saud University, P.O. Box 2455, Riyadh, 11451, Saudi Arabia

* Corresponding Author:

Chalcogenide Letters 2025, 22(3), 261-276. https://doi.org/10.15251/CL.2025.223.261

Received 22 December 2024; Accepted 25 March 2025;

Abstract

The combination of two-step synthesis processes is employed for the fabrication of (NiO)(_0.5)/(Fe₂O₃)(_0.5)@C@MoS₂ (NFCM) nanofibers composite through electrospinning and hydrothermal techniques. This nanofiber composite is designed for tunable dielectric materials and electromagnetic interference (EMI) shielding applications. Using impedance spectroscopy, the electrical properties of an NFCM pellet are analyzed using an equivalent circuit model (R₁1<), with a primary focus on the variation of relaxation time with frequency at different temperatures. Utilizing the Mott. variable range hopping (MVRH) model, and small polaronic hopping model, the localization length of the hoping carriers is determined to be 0.98 Å and the activation energy of thermally activated charge carriers is determined to be (E_a=.0.27eV). The activation energy calculated from the impedance, SPH model, and conductivity plot are inaudibly comparable representing the conduction and relaxation process associated with the same electroactive regions. The (NFCM nanofibers composite exhibits higher conductivity at all temperature ranges, which is a crucial attribute for effective EMI shielding applications. In the X-band frequency range (8.2–12.4 GHz), the calculated EMI shielding effectiveness of NFCM nanofibers composite is 24.25 dB, this qualifies them for use in high frequency applications.

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Keywords

EMI shielding, Dielectric constant, Tangent loss, Hydrothermal technique, Impedance spectroscopy, Electrospinning and nanofibers

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Cite This Article

APA Style

Anwar, U., Noor, N.A., Mumtaz, S., Moussad, I.M. (2025). Impedance spectroscopy insights into (NiO)(_0.5)/(Fe₂O₃)(_0.5)@C@MoS₂ nanofibers composite for tunable EMI shielding applications . Chalcogenide Letters, 22(3), 261–276. https://doi.org/10.15251/CL.2025.223.261

Vancouver Style

Anwar U, Noor NA, Mumtaz S, Moussad IM. Impedance spectroscopy insights into (NiO)(_0.5)/(Fe₂O₃)(_0.5)@C@MoS₂ nanofibers composite for tunable EMI shielding applications . Chalcogenide Letters. 2025;22(3):261–276. https://doi.org/10.15251/CL.2025.223.261

IEEE Style

U. Anwar, N.A. Noor, S. Mumtaz, and I.M. Moussad, “Impedance spectroscopy insights into (NiO)(_0.5)/(Fe₂O₃)(_0.5)@C@MoS₂ nanofibers composite for tunable EMI shielding applications ,” Chalcogenide Letters, vol. 22, no. 3, pp. 261–276, 2025. https://doi.org/10.15251/CL.2025.223.261

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