Here, High Energy Ball Milling (HEBM) is used to prepare Cr doped ZnO (Zn 1-x Cr x O, x = 0-0.04)... more Here, High Energy Ball Milling (HEBM) is used to prepare Cr doped ZnO (Zn 1-x Cr x O, x = 0-0.04) nanoceramics and their electrical behaviour is studied in detail. The X-ray diffraction suggests a hexagonal wurtzite structure. The Rietveld refinement XRD pattern of the sample calcined at 900 • C suggests that up to 4 at% of Cr can be doped into the ZnO structure. After sintering, the growth in the particle size was observed for Cr doped ZnO samples. The complex impedance behaviour of samples suggests a decrease in resistance with temperature. This shows the Negative Temperature Coefficient of Resistance (NTCR) characteristic of the Cr doped ZnO sample in the studied temperature range (300-500 • C). At higher temperature, the electrical relaxation behaviour is of the non-Debye type as observed from the relaxation time distribution. The equivalent electrical circuit of ZnO and Cr doped ZnO ceramic samples are a parallel arrangement of bulk capacitance (C b) and bulk resistance (R b).
In this study, monoclinic LiFeBO 3 was carbon-coated and iodine doped via a solid-state reaction ... more In this study, monoclinic LiFeBO 3 was carbon-coated and iodine doped via a solid-state reaction to improve the electrochemical performance of pristine LiFeBO 3 as cathode material in lithium-ion batteries. In order to enhance the electrical conductivity of LiFeBO 3 , the highly electronegative iodide anion was doped in a limited amount (x = 0.005) at the oxygen site of the borate to produce LiFeBO 3Àx I 2x. A thin carbon layer was then deposited in situ on the LiFe-BO 2.995 I 0.01 particles (to produce "LFBI/C") to protect them from air and moisture. Field-emission scanning electron microscopy (FE-SEM) data indicated the aggregated morphology of the synthesized samples. Powder X-ray diffraction (XRD) and 7 Li magic angle spinning (MAS) nuclear magnetic resonance (NMR) measurements revealed that both the doped and undoped LiFeBO 3based samples had mainly monoclinic structures, although a small amount of a vonsenite-type phase was formed upon iodine doping. X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray spectroscopy (EDX) data confirmed the successful insertion of iodine in the cathode material. The specific discharge capacity of LFBI/C at 0.05 C rate (144.68 mAh g À1) was higher than that of carbon-coated LiFeBO 3 (122.46 mAh g À1). The increased capacity of LFBI/C was also evident in long charge-discharge cycles conducted at 1 C rate and in the overall rate performance. Interestingly, the iodine-doped sample exhibited significantly high specific discharge capacity even at 10 C rate.
Globular amorphous carbonaceous materials embedded with graphite encapsulated metallic Co-nanopar... more Globular amorphous carbonaceous materials embedded with graphite encapsulated metallic Co-nanoparticles with a high degree of crystallinity are synthesized by pyrolysis and demonstrated as excellent candidates for optical limiters.
The surface morphology of the CI, GO, GO/PABA-CI, GO/Gly-CI and GO/Ala-CI composites was demonstr... more The surface morphology of the CI, GO, GO/PABA-CI, GO/Gly-CI and GO/Ala-CI composites was demonstrated by Scanning Electron Microscope (SEM). X-Ray Diffraction (XRD) patterns were recorded using a PANalytical X-ray diffractometer (operated at 40 kV and 150 mA) in a 2θ range of 5 to 90 (Cu-K α radiation, λ = 1.540 Å). Raman spectra of graphene oxide, PABA-CI, Gly-CI, Ala-CI, GO/PABA-CI, GO/Gly-CI and GO/Ala-CI samples were taken using a LabRam HR equipment (532 nm laser source).
The present work, Cr doped ZnO nanoceramics abbreviated as Zn 1-x Cr x O (x = 0, 0.01, 0.03) synt... more The present work, Cr doped ZnO nanoceramics abbreviated as Zn 1-x Cr x O (x = 0, 0.01, 0.03) synthesized by mechanical alloying. The structural, morphological, dielectric and optical properties of the synthesized samples were studied by using X-ray diffraction (XRD), Field Emission Scanning Electron Microscopic analysis (FE-SEM), UV-Visible spectroscopy (UV-Vis) and Impedance analyzer respectively. The structural parameters were measured by Rietveld method. The result shows the formation of single phase nanoceramics with hexagonal wurtzite structure with space group P6 3 mc. The crystallite size was found to decrease with increase in Cr concentration (~ 20 nm) and broadening of XRD peak exists in the samples. FE-SEM result shows that incorporation of Cr changes the surface morphology of ZnO. The band gap energy (E g) at room temperature was measured using Tauc relation and was found to decreases with increase in Cr concentration. The dielectric constant (ε) value of ZnO decreases with Cr doping and with increase in concentration the peak shifted towards higher temperature region.
Physical chemistry chemical physics : PCCP, Jan 21, 2017
Homogenously dispersed nanoparticles having a magnetic core and graphitic-carbon shells in amorph... more Homogenously dispersed nanoparticles having a magnetic core and graphitic-carbon shells in amorphous carbon globules are prepared using a low-cost pyrolysis technique. Synergetic microwave absorption in carbon globules embedded with nanoscale iron/iron-carbide graphite (FeC) particles via dielectric, magnetic and Ohmic losses is emphasized in this work. The electromagnetic interference (EMI) shielding properties of the FeC nanoparticles dispersed in polyvinylidene fluoride (PVDF) are studied in the 8-18 GHz frequency range and compared with those of PVDF composites containing similar weight fractions of conducting/magnetic phase micro-particles such as carbonyl iron (CI) or electrolytic iron (EI) or a similar amount of amorphous carbon phase such as amorphous carbon (a-C) globules. The PVDF/FeC composite shows a maximum SET value of -23.9 dB at 18 GHz, as compared to the SET for the other composites. The enhanced EMI shielding in the PVDF/FeC composite is attributed to the increased...
The present work, Cr doped ZnO nanoceramics abbreviated as Zn 1-x Cr x O (x = 0, 0.01, 0.03) synt... more The present work, Cr doped ZnO nanoceramics abbreviated as Zn 1-x Cr x O (x = 0, 0.01, 0.03) synthesized by mechanical alloying. The structural, morphological, dielectric and optical properties of the synthesized samples were studied by using X-ray diffraction (XRD), Field Emission Scanning Electron Microscopic analysis (FE-SEM), UV-Visible spectroscopy (UV-Vis) and Impedance analyzer respectively. The structural parameters were measured by Rietveld method. The result shows the formation of single phase nanoceramics with hexagonal wurtzite structure with space group P6 3 mc. The crystallite size was found to decrease with increase in Cr concentration (~ 20 nm) and broadening of XRD peak exists in the samples. FE-SEM result shows that incorporation of Cr changes the surface morphology of ZnO. The band gap energy (E g) at room temperature was measured using Tauc relation and was found to decreases with increase in Cr concentration. The dielectric constant (ε) value of ZnO decreases with Cr doping and with increase in concentration the peak shifted towards higher temperature region.
Using composites of polyvinylidene fluoride (PVDF) and carbon nanostructures embedded with Co-nan... more Using composites of polyvinylidene fluoride (PVDF) and carbon nanostructures embedded with Co-nanoparticles we demonstrate that electromagnetic shielding effectiveness depends strongly on the graphitic carbon concentration and the magnetic properties of Co-particles. Cobalt nanoparticles encapsulated by graphitic carbon embedded in an amorphous carbon-matrix were synthesized by a one-pot pyrolysis method at two different synthesis temperatures, T S = 800 1C (Co-800) and 1000 1C (Co-1000). We demonstrate that T S plays an important role in determining the structure, morphology and magnetic properties of the carbonaceous matrix, the graphite layer and the Co nanoparticles. Higher amounts of graphitic carbon and high saturation magnetization were observed for the Co-1000 sample than that for the Co-800 sample. We observed that the electromagnetic interference (EMI) shielding behavior of the PVDF-Co-1000 nanocomposite shows higher shielding effectiveness than that of the PVDF-Co-800 specimen. A more inhomogeneous dielectric medium in the PVDF-Co-1000 composite results in higher dielectric loss and impedance mismatch. A direct correlation between the shielding effectiveness with dielectric permittivity and magnetic permeability is demonstrated. The synergy between the multiple reflections at the interfaces and absorption of the microwave radiation in the conducting species confirms that a higher degree of graphitization and highly magnetic particles in nanocomposites are effectively superior for EMI shielding of microwave radiation.
Phase pure cobalt-ferrite (CoFe 2 O 4) and Zn-substituted CoFe 2 O 4 (Co 0.8 Zn 0.2 Fe 2 O 4 and ... more Phase pure cobalt-ferrite (CoFe 2 O 4) and Zn-substituted CoFe 2 O 4 (Co 0.8 Zn 0.2 Fe 2 O 4 and CoFe 1.8 Zn 0.2 O 4) nanopowders were synthesized by a glycine-nitrate auto-combustion route without any post-calcination process. The as-synthesized nano-ferrite powders were first pelletized, sintered and studied. Our results show that the crystallographic site preference of Zn, cation distribution, change in the oxidation state of Co-cation (+2 to + 3), and reduction in magnetic A-O-B superexchange interactions of the AB 2 O 4 type spinel structure have a direct consequence on the excellent magnetostriction behavior of the samples. Our results demonstrate that although the observed λ max values of the Zn-substituted samples are lower than the unsubstituted sample, importantly, the magnitude of the maximum strain sensitivity ([dλ/dH] max) of the Zn-substituted samples (~3.6 × 10-9 m/A) is nearly 300% higher than the parent compound (~1.18 × 10-9 m/A), even at remarkably low magnetic fields. This facilitates the direct use of our samples for highly sensitive strain sensor applications.
In this work, EMI shielding behaviors in the X-band frequency have been investigated for flexible... more In this work, EMI shielding behaviors in the X-band frequency have been investigated for flexible polyvinylidene fluoride (PVDF) composites containing globular-and tubular-shaped carbonaceous nanostructures embedded with mono-metallic (Ni) and bi-metallic (FeNi, CoNi, MnNi) alloy nanoparticles. Pyrolysis was carried out at two different temperatures (800 C and 1000 C) to synthesize carbonaceous materials with two different morphologies. Carbon nanotubes (CNTs) are predominantly seen in the samples synthesized at lower temperature (800 C), whereas carbon globules (CGs) are observed for the samples synthesized at higher temperature (1000 C). The PVDF-CNT composites show superior microwave shielding behavior than the PVDF-CG composites, which is attributed to the enhanced absorption of the microwave through Ohmic conduction and interfacial polarization loss. The 1-D structure of CNTs provides the required conduction path for the electrons and forms a network to trap the microwave within them via multiple scattering. The microwave absorption behavior of the composites predominantly results from the metallic nature of the embedded nanoparticles, the graphitic layer encapsulating them and the graphitic walls of the CNTs. We further demonstrate the direct correlation of the EMI shielding behavior of the nanocomposites with the morphology of carbonaceous nanomaterials and the conductivity of the embedded metallic nanoparticles.
Synthesis conditions, cation distribution at tetrahedral and octahedral sites and their stability... more Synthesis conditions, cation distribution at tetrahedral and octahedral sites and their stability play very important roles in controlling phase-purity and physicochemical properties of spinel ferrite compounds. In this work, an attempt is made to understand how the progress of phase-formation and the structural and magnetic properties are influenced by the annealing temperature and nature of cations used in the synthesis of quaternary spinel ferrite ceramics. A series of Co 0.8-x Mn 0.2 Zn x Fe 2 O 4 (x = 0, 0.2, 0.4, 0.6 and 0.8) (CMZF) spinel ferrite samples were synthesized by citric acid assisted sol-gel technique followed by annealing at 400, 600 and 800°C. To compare the progress of phase formation/stability of the cations, simple (binary) spinel ferrite reference samples, such as CoFe 2 O 4, MnFe 2 O 4 and ZnFe 2 O 4 , were also synthesized by the same technique and are calcined at the same conditions. In case of CoFe 2 O 4 , all the samples have single phase spinel structure, but a transformation from an inverse spinel-type to nearly normal spinel ferrite-type cation distribution is observed with increasing annealing temperature. The as-prepared MnFe 2 O 4 sample and that annealed at 400°C show formation of single phase spinel ferrite, while those annealed at 600 and 800°C decomposes completely into Mn 2 O 3 , α-Fe 2 O 3 and amorphous-FeO phases. In contrast, for ZnFe 2 O 4 samples, a transformation from the ZnO and α-Fe 2 O 3 phases (present in the as-prepared and up to 600°C annealed samples) to pure ZnFe 2 O 4-phase occurs only at/ above 800°C. Interestingly, our results show that the progress of the phase formation behavior of the CMZF samples can be predominantly considered as a combination of the behavior and energetics typically exhibited by the individual (simple) ferrite systems. Overall, our work provides the necessary impetus for achieving the phase purity and required physicochemical properties of complex ferrite systems by choosing the cations suitably, based on their nature and annealing behavior.
� Nanocrystalline Mg-doped Co-Ni-ferrite samples were prepared by sol-gel auto-combustion method.... more � Nanocrystalline Mg-doped Co-Ni-ferrite samples were prepared by sol-gel auto-combustion method. � Mg and Ni occupy the tetrahedral (T d) and octahedral (O h) sites of the spinel structure, respectively. � Co occupies both the T d and O h sites of the spinel structure in the ratio 2:3; Fe adjusts its occupation as required. � By Mg substitution for Ni, the coercivity remains constant but saturation magnetization decreases slightly.
The effect of variation of band gap and electronic defect energy levels within the band gap on no... more The effect of variation of band gap and electronic defect energy levels within the band gap on non-linear optical absorption of 532 nm (green) laser light by coral-like yttrium aluminium-iron garnet (YAIG, Y 3 Al 5-x Fe x O 12) ceramics prepared by solution combustion route is investigated using Z-scan technique. Our yttrium aluminium garnet (YAG) sample with band gap of �~ 6.5 eV, is transparent to visible light. The band gap of YAG was tuned by substituting Fe at the aluminium site and consequently, the surface defects in YAG were also modified. The defects in the YAIG samples introduce electronic defect states within the band gap. We observed that the intensity of the non-linear absorption (NLA) signal increases with increase in the amount of iron content. We assigned this enhancement of NLA signal to: (1) the decrease in the band gap from �~ 6.5 eV for YAG to ~ 2.6 eV for yttrium iron garnet (YIG) facilitating two photon absorption (2 PA) process rather than three photon absorption (3 PA), and (2) the increase in excited state absorption (ESA) due to the spread of the defect energy states into the band gap region. As the band gap gets closer to the photon energy of the laser, the non-linear optical absorption is enhanced due to ESA, in combination with the occurrence of the relatively stronger 2 PA process rather than the very weak 3 PA process. Our results demonstrate a method to tune the NLA performance of YAG through iron substitution at the Al sites and provide a better understanding of the non-linear absorption behaviour of YAIG ceramics for their application in optical limiting devices such as laser shields.
In this work, we demonstrate the importance of the free carrier absorption (FCA) process in the n... more In this work, we demonstrate the importance of the free carrier absorption (FCA) process in the nonlinear optical absorption (NLA) behavior of carbonaceous nanomaterials synthesized by pyrolysis at different heating rates (R h = 1, 3, 10, and 20°C/min). The chemical vapor deposition reaction through the pyrolysis of Ni(II) acetylacetonate, melamine, and toluene precursors was carried out at 600°C, which leads to different carbonaceous nanostructures embedded with graphite-encapsulated Ni nanoparticles (Ni@C samples). A lower R h (1 and 3°C/min) value leads to the formation of globular carbon aggregates embedded with core−shell-type Ni−graphite nanoparticles, whereas a high R h (10 and 20°C/min) value leads to the formation of carbon nanotubes embedded with similar Ni−graphite core−shell nanoparticles. The samples prepared at moderate heating rates of 3 and 10°C/min show prominently high NLA than those prepared at very slow or very fast (1 and 20°C/min) heating rates. According to our results, the quality (and the amount) of graphitization and nitrogen defect centers enhance the NLA behavior of the Ni@C samples. This result is obtained through the enhancement of excited-state absorption (ESA) behavior of the samples due to the introduction of defect states within the band gap of the graphite layer. More importantly, the metallic Ni nanoparticles help in drastically enhancing the NLA through the FCA process. To prove this supposition, we demonstrated that the presence of any dielectric phase (e.g., NiO) within the metallic nanoparticles (or within the sample) acts as a barrier to FCA, thereby reducing the NLA. Our work highlights the importance of synthesis conditions (optimized heating rate), especially in controlling the quality of graphitization and the embedded metallic Ni particles in the Ni@C samples in enhancing the NLA. Furthermore, through the mechanistic insights, we emphasized the potential use of our Ni@C samples for optical limiting applications because of their excellent NLA behavior originating through the FCA and ESA processes.
An effective solution for corrosion protection of metallic carbonyl iron (CI) substrates in stron... more An effective solution for corrosion protection of metallic carbonyl iron (CI) substrates in strong saline environment (3 M KCl) is demonstrated in this work. A thin layer coating of graphene oxide (GO) sheets enhances the corrosion inhibition behavior of amino acids that are directly grafted on metallic iron surfaces. The combined effect of GO and the corrosion inhibiting layer such as para-aminobenzoic acid (PABA), glycine, or alanine drastically improves the corrosion inhibition efficiency, in comparison to any of the single-layer coating, without considerably increasing the coating layer thickness. The microscopic origin of the corrosion protection efficiency of these layers is explained by the physical arrangement of the inhibitor molecules and the integrity of the GO sheets. According to our results, although a single layer of alanine provides better corrosion protection than that of a single layer of glycine or PABA, an additional coating of GO sheets effectively enhances the corrosion protection efficiency multifold. This comes with a concomitant advantage that glycine is economically much cheaper than alanine. Hence, our study demonstrates an economical way to achieve excellent efficiency in corrosion inhibition for metallic surfaces, making our technology exceptional for their direct implementation in environmental and industrial applications.
We report the structure, magnetic domain state and spin dynamics of biphasic Co nanoparticles emb... more We report the structure, magnetic domain state and spin dynamics of biphasic Co nanoparticles embedded in amorphous carbon matrix. Two types of samples were synthesized by heating the precursors (Co-acetylacetonate and toluene) from RT to the pyrolysis reaction temperature (800°C) at two different heating rates, viz. ∼ 3°C/ min and ∼20°C/min. We observe that the sample prepared at higher heating rate (∼20°C/min) predominantly contains fcc-phase of Co in the Co-nanoparticles, whereas the sample synthesized at lower heating rate exhibits higher amount of the hcp-phase-content in the Co-nanoparticles. The Co-nanoparticles are surrounded by graphitic carbon layers forming core-shell type morphology. The hcp-phase of Co is characterized by a higher saturation magnetization and coercivity (higher magnetic hardness) than the fcc-phase. The nature of the measured hysteresis loop in combination with the estimated critical size for the particles to be in a single magnetic domain state suggest that both hcp and fcc-phases of Co coexist in the same particle and most of the particles are multidomain-particles. Furthermore, our results reveal that the dynamics of the spins present at the grain boundaries are the slowest followed by those in the fcc-phase and hcp-phase of Co. The dynamics of the spins present at the domain walls are slower than those inside the magnetic domains. The responsive nature of the spins on the domain walls in comparison to those inside the domains leads to the so called domain wall enhancement effect.
A comprehensive investigation was carried out to explore the micro-mechanisms associated with the... more A comprehensive investigation was carried out to explore the micro-mechanisms associated with the evolution of deformation microstructure and texture in Ni-Fe alloys during rolling. X-ray diffraction, electron backscatter diffraction (EBSD) and Mössbauer spectroscopy as well as simulation methods involving crystal plasticity and molecular dynamics simulations were used to explore the mechanism of evolution. Pure Ni, Ni20wt.%Fe and Ni40wt.%Fe were rolled to true strain 3.0, following two different strain paths. Unidirectionally rolled Ni20wt.%Fe and Ni40wt.%Fe alloys show copper type texture, similar to that of pure Ni. By contrast, the cross rolled samples show the development of-fibre along with A {110} < 111 > and cube {100} < 001 > orientations. Both Ni20Fe and Ni40Fe exhibit extensive shear banding in UDR as well as CR conditions, unlike pure Ni, which has been attributed to the appearance of two short-range ordered phases, Ni3Fe and NiFe. In case of UDR, the nature of shear banding is different in Ni20Fe and Ni40Fe alloys, while after CR both the alloys show similar microstructures displaying higher fraction of shear banding compared to UDR. Simulation results have indicated that larger number of slip systems are activated in case of CR compared to the UDR samples that leads to the formation of a weaker texture in the former. Some strain free grains have been observed near the shear banded regions, indicating that an extended recovery mechanism could be operative in Ni20Fe and Ni40Fe. This phenomenon was more pronounced when the fraction of shear bands was more.
The changes in structure, infrared absorption and magnetic property of nanocrystalline Mn 0.5 Zn ... more The changes in structure, infrared absorption and magnetic property of nanocrystalline Mn 0.5 Zn 0.5 Sm x Fe 2-x O 4 (x = 0.01, 0.03 and 0.05) ceramics were studied after different doses (0, 15 and 25 kGy) of γ-irradiation. The samples were prepared by solution combustion route. We observed that up to the highest studied dose (25 kGy) of γ-irradiation all the samples retain the cubic spinel (Fd-3m) structure as of the pristine samples, however, the lattice parameter decreases. Furthermore, we observed the metastability of Sm (and Mn) atoms at the octahedral sites. By Sm 3+ doping the saturation magnetization of the pristine samples decreases, but the magnetic coercivity increases drastically, indicating enhancement of magnetic anisotropy. After γ-irradiation the magnetic anisotropy vanishes completely and the sample behaves super-paramagnetically with a small variation in saturation magnetization. Our results are important to understand the behavior and stability of the magnetic hardness created by Sm 3+ doping in soft magnetic Mn-Zn ferrite ceramics.
and 0.10) samples were synthesized by solution combustion synthesis method using metal nitrates a... more and 0.10) samples were synthesized by solution combustion synthesis method using metal nitrates as oxidizers and glycine as fuel. A spongy networktype microstructure is observed by the SEM micrographs of all the synthesized samples. For Fe concentration lower than 0.05 (x ≤ 0.05), formation of phase-pure wurtzite (hexagonal) structured Zn 1-x Fe x O powder with P6 3 mc space group was confirmed from the X-ray diffraction results. However, for x ≥ 0.07, precipitation of ZnFe 2 O 4 impurity phase was observed. Hence, the solubility limit for Fe in ZnO lattice is about x = 0.05 for the samples synthesized by solution combustion method. Two quadruple doublets observed in the 57 Fe-Mössbauer spectra for each of the samples suggest that paramagnetic Fe 3+ cations occupy two different lattice sites in the ZnO structure; they are the substitutional sites (1) without distortion of the surrounding structure and (2) with distortion due to the defects present in the surrounding structure. In the DRS spectra, an Urbach-like tail was observed in the band gap region, indicating that Fe-doping in the ZnO lattice modifies the electronic structure and enhances the absorption of visible light. Furthermore, the Kubelka-Munk plots suggest the presence of two different local structures validating the Mössbauer results. We studied the photocatalytic degradation of methylene blue dye using these Fe doped ZnO samples as catalysts and the studies revealed that presence of Fe could lead to the formation of carbonaceous material on the surface of the solution combustion synthesized Zn 1x Fe x O samples. Overall, our results demonstrate the structural characteristics of Fe in Fe-doped ZnO samples synthesized by solution combustion method.
In this work, we have used a single-step pyrolysis method in synthesizing carbonaceous materials ... more In this work, we have used a single-step pyrolysis method in synthesizing carbonaceous materials at 800 1C and 1000 1C, using metal (Ni-or Mn-) acetylacetonate and toluene as precursors. We demonstrated that the pyrolysis synthesis temperature (T P) and the choice of organometallic precursors affect the morphology and the microstructure of the carbonaceous materials. Namely, at low temperature (800 1C), the Ni(acac) 2 precursor leads to the formation of metallic-Ni catalysts for the growth of carbon nanotubes (CNTs), but at high temperature (1000 1C) this favors the growth of carbon globules (CG). In contrast, the Mn-(acac) 2 precursor leads to the formation of MnO-particles, and associated carbon globules at both the temperatures used. The electromagnetic interference (EMI) shielding effectiveness (SE) of the PVDF polymer based composite specimens prepared with the carbonaceous samples having a metallic Ni-core is found to be far superior than that obtained using the specimen with particles of the MnO-core. The observed contrast in SE behavior is shown to originate due to the size and metallic nature of the Ni-nanoparticles and the Ohmic conduction loss in these metallic particles over the loss due to interfacial polarization-based scattering of the insulating MnO nanoparticles present in the PVDF-based composite films. Hence, our study highlights the necessary synthesis parameters, and the importance of graphite coated metallic nanoparticles in designing highly efficient EMI shields.
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Papers by Rajeev Kumar