Transition metal impregnated nanostructured oxide material for broadband electromagnetic interference shielding: A theoretical and experimental insight

Paul, Biplab Kumar; Mondal, Dheeraj; Bhattacharya, Dhrubajyoti; Datta, Soumendu; Kundu, Manab; Mondal, Indranil; Halder, P.; Sarkar, Shaibal K.; Ghosh, Amrita; Mandal, Tripti; Das, Santanu

doi:10.1016/j.cej.2023.141560

Cited by 15 publications

(15 citation statements)

References 61 publications

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“…The crystallite size ⟨ D ⟩ can be calculated using the Debye–Scherrer formula, , ⟨ D ⟩ false( 211 false) = 0.9 × λ β 1 / 2 cos 0em0.25em⁡ θ where β 1 / 2 is the full width at half-maximum (fwhm) of the diffraction peaks and λ is the wavelength of incident X-ray radiation. The corresponding value of microstrains (ε) of the samples are calculated from the most intense peak using the formula ε = β h k l 4 tanθ …”

Section: Resultsmentioning

confidence: 99%

“…Based on availability, cost, toxicity, and applicability in industry, MnO 2 draws great attention among the transition metal oxides . Due to exhibiting layer type and tunnel structure, all the desired properties can be true. − Among different crystallographic polymorphs (i.e., α, β, γ, δ, ε, λ, and R), − the α-phase of MnO 2 has piqued researchers’ interest because it can exhibit 1D 2 × 2 (0.46 nm × 0.46 nm) tunnel like tetragonal structure developed by sharing edges and corner atoms of octahedral MnO 6 unit (space group I 4/ m ). ,, This tunnel elongates along the c -axis and forms a densely packed wall to the tunnel. Additionally, a number of cations of different sizes can also be substituted to engineer the central tunnel.…”

Section: Introductionmentioning

confidence: 99%

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Rare Earth Ion-Doped α-MnO₂Nanorods for an Asymmetric Supercapacitor

Mondal,

Kundu,

Paul

et al. 2024

ACS Appl. Nano Mater.

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The limited electrical conductivity of manganese dioxide (MnO 2 ) hinders its broad use as an electrode in all-solid-state supercapacitor devices (ASDs). To overcome this, trivalent gadolinium (Gd) and erbium (Er) ions are incorporated into MnO 2 , effectively addressing the issue. This involves synthesizing α-MnO 2 nanorods infused with Gd and Er by using a modified chemical process. Through the creation of crystal defects, augmentation of electrical conductivity, and increased porosity, the electrochemical performance is significantly enhanced. Cyclic voltammetry and galvanostatic charge− discharge measurements within the range of −0.2 to +0.6 V unveil improved capacitance values of 798 and 647 F g −1 at 1 A g −1 current density for Gd-and Er-doped α-MnO 2 respectively, maintaining 92.4% and 89.7% charge retention after 5000 cycles. Analysis reveals that both samples are primarily dominated by electric double-layer capacitance (EDLC). Furthermore, surface capacitance outweighs diffusion-controlled processes in the electrochemical storage mechanism. The Gd-doped α-MnO 2 coated device depicts a peak energy density of 78.5 Wh kg −1 at 106.01 W kg −1 power density for 0.5 A g −1 and maximum power density of 498.1 W kg −1 at 9.13 Wh kg −1 energy density for 3 A g −1 . Even a handcrafted 1 cm × 1 cm device achieves 2.252 V potential, effectively illuminating commercial LEDs.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Rare Earth Ion-Doped α-MnO₂Nanorods for an Asymmetric Supercapacitor

Mondal,

Kundu,

Paul

et al. 2024

ACS Appl. Nano Mater.

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“…This reduction is attributed to the introduction of Sm 3+ through doping, which is potentially linked to the enhancement of both intrinsic and/or extrinsic characteristics at the grain boundary. [47,48,49] The dielectric loss value at 1 kHz was found to be 0.37, 0.08, and 0.04 for the x = 0.05, x = 0.10, and x = 0.20 Sm-doped of BCTO ceramics, respectively. Impedance spectroscopy is a prominent technique for the determination of the grain boundary and grain responses in order to understand the fundamental mechanisms underlying the dielectric and electrical results.…”

Section: Dielectric Measurementmentioning

confidence: 96%

“…which is consistent with the IBLC model. [48] To comprehend the conduction mechanism, the variation of AC conductivity with temperature was assessed. Figure 10 a depicts the temperature-dependent AC conductivity at 1 kHz for three distinct concentrations (x = 0.05, 0.1, 0.2) of BSCTO ceramics.…”

Section: Dielectric Measurementmentioning

confidence: 99%

Phase Evolution, Dielectric, and Electric Behavior of Sm‐Doped BCTO Ceramic Fabricated by Semi‐Wet Method

Prajapati,

Rai,

Kumar

et al. 2024

Cryst. Res. Technol.

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Bi(2/3)‐xSmxCu3Ti4O12 (BSCTO x = 0.05, 0.10, and 0.20) ceramics are synthesized using semi‐wet technique and an extensive investigation into their structural, morphological, and elemental properties, alongside dielectric and impedance behaviors, is meticulously carried out. X‐ray powder diffraction analysis unequivocally confirmed the formation of a monophasic BCTO cubic phase without any discernible secondary phases. and the crystallite size of the BSCTO ceramic, obtained by X‐ray diffraction using Debye Scherrer formula, range from 62 to 81 nm. Rietveld analysis reveals that ceramics have a body centered cubic structure with space group Im‐3. The Scanning electron microscope image displays the dense microstructure of the ceramics, while EDX analysis unveils the elemental composition of resulting products. Doping with Sm3+ induced a notable reduction in grain size, as observed through Scanning electron microscope and Atomic Force Microscope analyses, indicating Sm3+ hindered grain growth during sintering, potentially resulting in reduced dielectric constant (ε′). Dielectric constant and dielectric loss of the composition (x = 0.2) are found to be ≈152 and 0.04, respectively at room temperature (1 kHz). Impedance characteristics revealed a substantial increase in grain boundary resistance, leading to improved dielectric loss. The AC conductivity of BSCTO ceramics exhibited a frequency‐dependent increase satisfying to Johncher's power law.

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“…At the vicinity of valence band maxima (VBM), the band dispersion demonstrates a smooth line for both samples Mn8GdO16 (Figure4h) and Mn8ErO16 (Figure4i) whereas, near conduction band minima (CBM), the band dispersion is though almost plane for Mn8GdO16 but some curvature appears in the Mn8ErO16. The smoothness of bands near CBM or VBM indicates good charge carrier transportation or good conductivity[31]. In the pure α-MnO2, the O-2p states and Mn-3d state are mainly responsible for the formation of the valence band, while the major contribution comes from the O-2p states.…”

mentioning

confidence: 99%

Theoretical and Experimental Observations on Empowered EMI Shielding of Rare Earth Ion Infused α-MnO 2 Nano-rods

Mondal

Bhattacharya

Mondal

et al. 2023

Preprint

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In this communication, for the first time rare earth elements like Gd3+ and Er3+ ions are impregnated into the α-MnO2 tunneled structure involving the modified chemical synthesis route followed by hydrothermal technique. X-ray diffraction patterns and Raman spectroscopy confirm the proper phase formation without any impurity. A theoretical in-depth DFT study for the electronic bands and variation of density of states with the infusion of rare earth elements into the host structure confirms the experimental findings and depicts the suitability of the material towards the EMI shielding application. The novel synthesis technique helps to achieve uniform nanorod formation with a high specific surface area. Doping-induced defects, high surface-to-volume ratio, Maxwell-Wagner–Siller interfacial polarization, etc lead to achieving high dielectric response with moderate tangent loss at frequency range 40Hz to 1MHz. Temperature-dependent dielectric behavior indicates the paramagnetic to ferromagnetic transition at 120 \(℃\) and 70 \(℃\) for the Gd- and Er-doped α-MnO2 samples respectively. The electromagnetic interference (EMI) shielding effectiveness (SE) has achieved a maximum of − 43 dB at 15.3 GHz and − 46 dB at 15.3 GHz for Gd- and Er-doped α-MnO2 thin layer of thickness ∼600 µm respectively. Higher dipolar polarization, loss tangent, conductive pathways, and defects inside the crystal lead to attaining a high EMI shielding efficiency. This result reveals > 99.999% EMI SE against the hazardous electromagnetic waves in the microwave/GHz frequency region.

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Transition metal impregnated nanostructured oxide material for broadband electromagnetic interference shielding: A theoretical and experimental insight

Cited by 15 publications

References 61 publications

Rare Earth Ion-Doped α-MnO₂Nanorods for an Asymmetric Supercapacitor

Rare Earth Ion-Doped α-MnO₂Nanorods for an Asymmetric Supercapacitor

Phase Evolution, Dielectric, and Electric Behavior of Sm‐Doped BCTO Ceramic Fabricated by Semi‐Wet Method

Theoretical and Experimental Observations on Empowered EMI Shielding of Rare Earth Ion Infused α-MnO 2 Nano-rods

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Transition metal impregnated nanostructured oxide material for broadband electromagnetic interference shielding: A theoretical and experimental insight

Cited by 15 publications

References 61 publications

Rare Earth Ion-Doped α-MnO2Nanorods for an Asymmetric Supercapacitor

Rare Earth Ion-Doped α-MnO2Nanorods for an Asymmetric Supercapacitor

Phase Evolution, Dielectric, and Electric Behavior of Sm‐Doped BCTO Ceramic Fabricated by Semi‐Wet Method

Theoretical and Experimental Observations on Empowered EMI Shielding of Rare Earth Ion Infused α-MnO 2 Nano-rods

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Rare Earth Ion-Doped α-MnO₂Nanorods for an Asymmetric Supercapacitor

Rare Earth Ion-Doped α-MnO₂Nanorods for an Asymmetric Supercapacitor