In this work, manganese zinc ferrite-reduced graphene oxide (MZFO-rGO) nanocomposites with different rGO contents (20, and 40 wt %) were synthesized using a simple and efficient in-situ sol–gel autocombustion method. X-ray diffraction (XRD) confirms the formation of a cubic spinel crystal structure in the nanocomposites, while peak broadening indicates nanocrystallinity with crystallite-sizes ranging from 13.6 to 10.5 nm upon rGO incorporation. Scanning electron microscopy (SEM) reveals the dispersion of MZFO nanoparticles over wrinkled rGO sheets, forming interconnected composite morphology. Fourier-transform infrared spectroscopy (FTIR) further verifies the integration of MZFO with rGO through characteristics vibrational bands. Electrical measurement demonstrates systematic increases in conductivity with increasing rGO content due to the formation of conductive sp2 carbon networks. Dielectric studies reveal that the MZFO-rGO40% composite exhibits the highest dielectric permittivity (ε′<InlineEquation ID="IEq1"> <EquationSource Format="TEX">$\sim$</EquationSource> <EquationSource Format="MATHML"><math> <mo>∼</mo> </math></EquationSource> </InlineEquation> 1.48 × 104 at 102 Hz) along with enhanced ac conductivity (<InlineEquation ID="IEq2"> <EquationSource Format="TEX">$\sigma \text{a}\text{c} \sim 6.4$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>σ</mi> <mtext>ac</mtext> <mo>∼</mo> <mn>6.4</mn> </mrow> </math></EquationSource> </InlineEquation>× 10–6 Sm−1), due to reduced grain-boundary resistance and improved charge transport. Modulus and impedance analysis confirmed non-Debye relaxation behavior and enhanced electrical transport pathways, while semi-quantitative percolation analysis suggested the formation of interconnected conductive networks responsible for conductivity enhancement. Magnetic measurements revealed soft ferromagnetic behavior for all samples. The saturation magnetization (Ms) decreases from 36.46 emu/g for bare MZFO to 23.09 emu/g for MZFO-rGO20wt%, followed by a partial recovery to 27.90 emu/g for MZFO-rGO40wt% due to the combined effects of magnetic dilution, surface disorder, and improved nanoparticle dispersion. These findings highlight the potential of MZFO-rGO nanocomposites for application in energy storage, sensing and EMI shielding.

Electrical transport, dielectric behavior and magnetic properties of rGO-integrated MZFO nanocomposites synthesized via facile sol–gel autocombustion route

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发表日期：

2026年5月24日

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Sanjeev Kumar,
Rajesh Kumar,
Nagesh Thakur

摘要

In this work, manganese zinc ferrite-reduced graphene oxide (MZFO-rGO) nanocomposites with different rGO contents (20, and 40 wt %) were synthesized using a simple and efficient in-situ sol–gel autocombustion method. X-ray diffraction (XRD) confirms the formation of a cubic spinel crystal structure in the nanocomposites, while peak broadening indicates nanocrystallinity with crystallite-sizes ranging from 13.6 to 10.5 nm upon rGO incorporation. Scanning electron microscopy (SEM) reveals the dispersion of MZFO nanoparticles over wrinkled rGO sheets, forming interconnected composite morphology. Fourier-transform infrared spectroscopy (FTIR) further verifies the integration of MZFO with rGO through characteristics vibrational bands. Electrical measurement demonstrates systematic increases in conductivity with increasing rGO content due to the formation of conductive sp² carbon networks. Dielectric studies reveal that the MZFO-rGO40% composite exhibits the highest dielectric permittivity (ε′ $\sim$ $\sim$ 1.48 × 10⁴ at 10² Hz) along with enhanced ac conductivity ( $\sigma \text{a}\text{c} \sim 6.4$ $σ ac \sim 6.4$ × 10^–6 Sm⁻¹), due to reduced grain-boundary resistance and improved charge transport. Modulus and impedance analysis confirmed non-Debye relaxation behavior and enhanced electrical transport pathways, while semi-quantitative percolation analysis suggested the formation of interconnected conductive networks responsible for conductivity enhancement. Magnetic measurements revealed soft ferromagnetic behavior for all samples. The saturation magnetization (Ms) decreases from 36.46 emu/g for bare MZFO to 23.09 emu/g for MZFO-rGO20wt%, followed by a partial recovery to 27.90 emu/g for MZFO-rGO40wt% due to the combined effects of magnetic dilution, surface disorder, and improved nanoparticle dispersion. These findings highlight the potential of MZFO-rGO nanocomposites for application in energy storage, sensing and EMI shielding.