Impedance spectroscopy insights into (NiO)(0.5)/(Fe2O3)(0.5)@C@MoS2 nanofibers composite for tunable EMI shielding applications

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 (R1Q1), 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 (Ea=.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.