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Oxalyldihydrazide (ODH) and coffee extracted fuel (CEF) were used to synthesize Ceria (CeO 2) nanoparticles by solution combustion synthesis route. The cubic fluorite structure, crystalline nature, crystallite size and particle size of ceria nanoparticles were confirmed using the powder X-ray diffraction (PXRD) and High-Resolution Transmission Electron Microscope patterns respectively. Field Emission Scanning Electron Microscope (FESEM) images were used to understand the Surface morphology of the synthesized samples. Based on XRD results the volume of coffee husk extract for the optimum phase formation is found to be 40 mL. The fluorite structure of the samples and the presence of oxygen vacancies in the samples were confirmed from the Raman spectral analysis. ESR (Electron Spin Resonance) studies confirmed formation of relatively more intrinsic defects in CEF-ceria nanoparticles compared to ODH-ceria nanoparticles. The semiconducting nature of the synthesized samples was confirmed by analysing UV–visible absorbance spectra. The functional group confirmation was obtained by analysing Fourier Transform Infrared (FTIR) spectra of both the samples. AC conductivity and dielectric relaxation studies of the samples in pellet form were carried out over a wide frequency (20Hz–10 MHz) and temperature (200–640 °C) range using a precision impedance analyser. A higher value of dielectric constant was observed for CEF-ceria nanoparticles. [ABSTRACT FROM AUTHOR]

In this study, polymer composite nanofibers and thin membranes were synthesized using Carbon Nanotubes (CNTs) and Zinc Oxide (ZnO) as fillers in a Polyvinyl Alcohol (PVA) matrix, aiming to evaluate their electrical and mechanical properties. The composite nanofibers and thin membranes were prepared by incorporating different weight ratios of CNTs and ZnO into the PVA matrix using electrospinning and solution casting techniques, respectively. Solutions were prepared by mixing specific weight ratios of PVA, ZnO, and CNTs, followed by magnetic stirring and ultrasonication for homogenization. Electrospinning was performed at 20 kV with a syringe-to-collector distance of 14.5 cm at flow rate of 2.4 ml/hr. The composites were characterized using FTIR spectroscopy and Scanning Electron Microscopy (SEM). The PVA/5%ZnO/0.5%CNT composite exhibited the highest dielectric constant of 10.3 at high frequencies, while PVA/5%CNT showed the highest capacitance of 31.1 pF at 2 MHz. The maximum AC conductivity of 2.72 × 10− 7S/m was also observed for the PVA/5%ZnO/0.5%CNT composite. Mechanical testing revealed significant improvements in Young's modulus, stress yield, and load yield, with PVA/5%CNT achieving a Young's modulus of 387.12 MPa and a stress yield of 6.92 MPa. The addition of ZnO and CNT fillers resulted in enhanced electrical and mechanical properties, making these composites suitable for applications in microelectronic devices and packaging materials. [ABSTRACT FROM AUTHOR]

For the first of its kind, Cr 3 + -substituted calcium hexaferrite (CaCrxFe 1 2 − x O 1 9 (x = 1 , 3, 5 and 7)) nanoparticles (NPs) were synthesized via a facile, economical, eco-friendly lemon juice extract mediated green solution combustion method. The samples were calcined followed by characterization. The Bragg reflections confirm the formation of a single phase M-type hexaferrite crystal structure. No other impurity or mixed phases are observed even after the substitution of Cr 3 + to the host matrix. Meanwhile, the crystallite size decreases from 29.44 to 19.92 nm with an increase in the substitution of Cr 3 + ions. The surface morphological analysis shows the presence of agglomerated irregularly shaped NPs. The direct energy band gap estimated using Wood and Tauc's relation depicts the decrease in energy band gap from 2.98 to 2.74 eV with an increase in the substitution of Cr 3 + ions. These Cr 3 + -substituted calcium hexaferrite NPs were predicted to be useful in high-frequency applications based on structural, dielectric, and magnetic studies. [ABSTRACT FROM AUTHOR]

Polymer nanocomposites are promising for various industrial and scientific applications due to their flexibility, diverse functionalities, and unique properties. In this study, zinc oxide nanorods (ZnO NRs) were incorporated into a blend of polymers (Hydroxypropyl methylcellulose - HPMC and Polyvinyl pyrrolidone - PVP) using a solution-casting technique, with concentrations varying from 2 % to 8 % by weight. Transmission electron microscopy (TEM) revealed that the ZnO NRs had an average diameter of 140 nm and a length of 3.22 μm. X-ray diffraction (XRD) analysis showed reduced crystallinity in the samples as the ZnO NR content increased. Fourier-transform infrared spectroscopy (FTIR) indicated changes in vibrational peaks due to interactions between functional groups in the blend and the nanorods. The addition of ZnO NRs significantly influenced the optical bandgap energies and UV/visible light absorption spectra of the samples. The bandgap of the nanocomposites significantly decreased upon ZnO NR incorporation, with direct and indirect bandgaps ranging from 5.19 to 4.70 eV and 4.74–3.66 eV, respectively. Electrical conductivity and dielectric characteristics were assessed across frequencies ranging from 0.1 to 10 MHz, revealing increasing AC conductivity, dielectric permittivity, and dielectric loss with higher ZnO NR content. Notably, at 10 Hz, the electrical conductivity increased from 3.5 × 10⁻12 S/m to 3.62 × 10⁻10 S/m upon loading with ZnO NR. The combination of adjustable optical bandgaps, frequency-dependent AC conductivity, and a wide range of tunable permittivity highlights the potential of these HPMC/PVP-ZnO NR nanocomposites for developing flexible optoelectronic and energy storage devices. [ABSTRACT FROM AUTHOR]

Pure and 6% Ag doped bismuth sulfide (Bi2S3) were synthesized via solid‐state reaction method at 500 °C. The X‐ray diffraction method confirmed the orthorhombic phase with average crystallite size ∼25 nm and average lattice strain ∼0.5% and ∼0.6% for pure and 6% Ag doped Bi2S3. The scanning electron microscope (SEM) images confirmed nanobelt morphology. A direct bandgap of ∼3.3 and ∼3.4 eV for pure and doped Bi2S3 was estimated using UV–vis spectroscopy, respectively. AC measurements were performed from 200 Hz to 2 MHz at temperature 223–298 K. Investigation of Nyquist plots of 6% Ag doped Bi2S3 nanobelts suggested space‐charge‐dependent behavior and indicated an negative temperature coefficient of resistance (NTCR). AC conductivity adhered to Jonscher's power law in which the decreasing trend of s‐parameter with increasing temperature indicates correlated barrier hopping conduction mechanism. From this model, hopping distance (∼10−9–10−11 m) and density of states (∼1022–1023 eV−1 cm−3) were estimated. The dielectric permittivity exhibited dispersion at low frequencies due to the combined effect of electronic, ionic, and interfacial polarizations. Presence of two semicircular arcs in the complex modulus analysis suggested the presence of both grain and grain‐boundary effects. [ABSTRACT FROM AUTHOR]

The prospective applications of carbon graphene nanoplatelets (GNPs) reinforced ethylene vinyl acetate (EVA) nanocomposites in flexible electronics, energy storage devices, and thermal management systems have attracted a lot of attention. These nanocomposites offer an effective solution for enhancing the electrical conductivity of interfacing materials in electronic systems and addressing issues related to thermal management. GNPs that possess excellent thermal conductivity of 2000–4000 W m−1 K−1 and an electrical conductivity of 107 S m−1 are utilized in this investigation. The homogeneous dispersion of nanofiller and the effective load transfer between components through strong filler/polymer interfacial interactions are essential for the creation of multifunctional polymer nanocomposites. Particularly, their electrical conductivity and dielectric properties are highlighted in this study, with an emphasis on the synthesis and characterization of nanocomposite materials. This work investigates the utilization of graphene nanocomposites in EVA using a melt‐mixing technique assisted by sonication to fabricate multifunctional composites. Incorporating different weight percentages of GNPs (ranging from 0.1 to 0.4 wt.%) within the polymer matrix is carried out. In the present study, the nanocomposites are characterized by scanning electron microscopy investigation and impedance spectrum analysis. The distinctive characteristics of the AC electrical transport in nanocomposites are investigated between 10 Hz and 1 MHz. Excellent interfacial compatibility has been demonstrated by the homogenous distribution of GNPs within the matrix, confirmed by SEM examination. These EVA nanocomposites demonstrate improved electrical conductivity, thereby rendering them very useful for energy storage applications, such as electronic capacitors, wherein supports with a significant dielectric constant and minimal dielectric loss are required. [ABSTRACT FROM AUTHOR]

Photocatalysts that combine with dielectric and magnetic properties are vital because of a wide variety of applications for these combinations, and nanostructured magnetic semiconductive materials have attracted significant interest due to their potential applications. A series of Cd 0.4 Co 0.6 Dy X Ce X Fe 2-2X O 4 spinel nano ferrites (nFs) were synthesized by using a highly efficient low-temperature method of citrate sol-gel auto-combustion for Methylene Blue (MB) dye degradation photocatalysts under visible light irradiation that combines with dielectric and magnetic properties are vital because of a wide variety of applications for these combinations, and nanostructured magnetic semiconductive materials have attracted significant interest due to their potential applications. The recycled MB is one of the hazardous textile dyes that is used extensively but causes risks for both humans and the environment. The prepared Dy3+ and Ce3+ doped Cd–Co nFs were polycrystalline with cubic structure, and crystalline size was increased from 15.78 to 21.02 nm with higher crystallinity, and the surface morphology changes from a spherical shape to a hexagonal shape with higher doping concentrations. The direct optical band gap values are increased. FTIR spectra reveal the stretching vibrations along the [M↔O] bond tetrahedral (A) and octahedral (B) sites. HRTEM results revealed that the prepared Cd–Co nFs have higher crystalline nature and high porosity. VSM indicates the sample's soft magnetic action and hysteresis loops showed the highest saturation magnetization (Ms) is 12.243 emu/g, and retentivity increases around 6.038 emu/g, decreasing the dielectric tangent loss, dielectric constant and dielectric loss. The AC conductivity raised with applied frequency. The PL gives a blue emission, and photocatalytic has the highest degradation activity 40.93 % of MB would be successful after 120 min irradiation of X = 0.07 Dy3+ and Ce3+ doped Cd–Co nFs. [Display omitted] [ABSTRACT FROM AUTHOR]

Nanocrystalline cobalt ferrites co-substituted with rare earth Ho and Er (CoFe 2-2 x Ho x Er x O 4 , 0 ≤ x ≤ 0.10) have been synthesized via the sol-gel method. X-ray Diffraction (XRD) confirmed the single-phase spinel structure with reduced crystallite sizes (65 nm–12 nm), micro-strain (ε) and increased lattice constant (a) with Ho–Er co-substitution. Rietveld refinement and theoretical computation revealed Ho and Er occupancy at octahedral sites and Fe and Co ions redistribution between the tetrahedral and octahedral sites. Infrared spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray spectroscopy (EDX) and X-ray Photoelectron Spectroscopy (XPS) supported the formation of the desired spinel structure, aggregated spherical morphology, chemical stoichiometry and elemental states. Magnetic measurements showed a systematic decrease in saturation magnetization (M s), magnetocrystalline anisotropy (K 1), coercivity (H c) and Curie temperature (T c) with Ho–Er co-substitution. Electron Spin Resonance (ESR) exhibited asymmetric resonance peaks, reduced resonance field (H r), linewidth (ΔH pp) and deviation in Lande g values. Impedance spectroscopy revealed two conduction mechanisms (holes and electrons) with distinct activation energies (E aI and E aII). Modulus spectrum analysis confirmed the thermally activated sample-electrode effects and the Nyquist plots indicated the dominant contribution of the grain boundary resistance to the conduction process. A notable enhancement in the dielectric constant (ε′) was observed with Ho–Er co-substitution. The ac conductivity (σ ac) followed the Jonscher Power Law (JPL). The temperature-dependent frequency exponent s(T) , suggests the existence of two conduction mechanisms: non-overlapping small polaron tunneling (NSPT) and correlated barrier hopping (CBH). [ABSTRACT FROM AUTHOR]

The crystal structure of La 0.7 Sr 0.3 Mn 1−x Al x O 3 (LSMAO) with x = 0,0.025,0.05,0.075 and 0.10 ceramics prepared by the Sol-gel method were investigated by employing the XRD technique. The XRD patterns analysis by employing the Rietveld analysis confirms the nonexistence of secondary crystal phase/s and, materials are crystallized to the R-3c(167) space group. The microstructural properties were studied using scanning electron microscope (SEM) and transmission electron microscope (TEM). The dielectric property, AC conductivity, complex impedance spectroscopy and complex electrical modulus have been studied over a wide range of frequencies (103 Hz–107 Hz) at different temperatures from 313K to 393K. The Non-Debye type relaxation process has been observed in synthesized samples confirmed from the Nyquist plot. The Cole-Cole plots were employed to estimate the individual grain and grain boundary contributions. The Maxwell-Wagner (MW) polarization model provides an explanation for the greater values of dielectric constant at the lower frequencies. The present study explores the technological usefulness of LSMAO. [ABSTRACT FROM AUTHOR]

Lithium Aluminosilicate glass-ceramics with striae (LAS-WS) and without striae (LAS-WoS) were processed using melt casting technique. LAS-WS and LAS-WoS samples were characterized and found stress birefringence >10 nm/cm and <10 nm/cm, respectively. LAS-WS and LAS-WoS samples were subjected to structural, microstructural, high temperature dielectric and electrical characterization. The presence of striation did not significantly affected the formation of β-spondumene structure during crystallization heat treatment. TEM image confirms the formation of nanocrystals in the glass matrix of lithium aluminosilicate glass-ceramics. The homogeneous distribution of LAS nanocrystals of average size of 3–6 nm is evident from TEM results. Stress birefringence distribution in lithium aluminosilicate glass-ceramic clearly shows the striae formation. Shadowgraphy images confirmed the striae free and striae containing regions in the glass-ceramic. The effect of striae on dielectric properties and AC conductivity was analysed using impedance spectroscopy and it was found that the value of the relative permittivity decreased from 415 (1.2 Hz) to 9.76 (1.2 MHz) for LAS-WoS and from 401 (1.2 Hz) to 10.3 (1.2 MHz) for LAS-WS, respectively. It was found that striae in LAS glass-ceramics influence the electrical impedance and AC conductivity relaxation process rather than relative permittivity. The effect of striae on crystallization and morphology are presented. Both the samples have shown crystallinity of more than 75 %. The electrical conductivity of σ = 2.0 × 10−3 S/cm for LAS-WoS and 2.7 × 10−3 S/cm for LAS-WS at 300 °C as well as σ = 4.6 × 10−3 S/cm for LAS-WoS and 6.9 × 10−3 S/cm for LAS-WS at 700 °C are found to be in good agreement due to increase in the electrical conductivity with temperature. The ionic conductivity of the material due to Li-ion mobility with respect to temperature and electric field and possible mechanism of AC conductivity are discussed. The results presented indicates the potential application of this material that demands high temperature operation of lithium aluminosilicate glass-ceramics. [ABSTRACT FROM AUTHOR]

The dielectric characteristics of double perovskite La2Ni1 − xFexMnO6; (x = 0, 0.2, 0.5, 0.8 & 1.0) developed via sol-gel route, were studied through analysis of B-site cation substitution. La2Ni0.8Fe0.2MnO6 attained a higher dielectric constant than pure La2NiMnO6 owing to comparatively higher B-site cationic disorder. The crystallite size and strain were determined using Williamson-Hall analysis, and strain in samples decreased with increasing Fe substitution. High-resolution transmission electron microscopy (HRTEM) authenticated the crystalline nature and selected area electron diffraction patterns (SAED) confirmed the purity of the sample. X-ray photoelectron spectroscopy (XPS) confirmed the co-occurrence of different oxidation states. Dielectric constant and tangent loss of overall composition decreased with frequency, while AC conductivity increased. AC conductivity decreased upon Fe-substitution and was strongly affected by the degree of B-site cationic disorder. Cole-cole plots and combined variation of Z″ & M″ with frequency suggested non-Debye relaxation in developed compositions. The tuned dielectric parameters suggest the possible applicability of developed double perovskite materials for fabricating energy storage devices. [ABSTRACT FROM AUTHOR]

Nanocrystalline Nd1 − xCexFeO3 samples (where, x = 0.00, 0.03, 0.05, & 0.07) were synthesized through the sol-gel citrate method to explore their structural, optical, electrical, and ferroelectric properties. Analysis of X-ray diffraction (XRD) data allows for the determination of phase purity and crystallinity. The data obtained from XRD pattern, along with Rietveld refinement, reveals an orthorhombic structure with the space group Pbnm. For every sample, the unit cell characteristics, such as bond lengths and bond angles are determined. The application of the Scherrer equation reveals that the calculated crystallite size falls within the range of 12–15 nm. The distinctive bands observed in FTIR spectra serve as additional confirmation of the desired sample formation. From the absorption study of the synthesized powder samples, the optical band gap comes out to be within the range of 2.68–2.84 eV. SEM images depict grains of diverse size with well-defined grain boundaries and irregular shapes. Elemental composition, verified through EDX spectra, reveals the absence of impurity elements. Adding a small amount of Cerium (Ce) to NdFeO3 creates a promising material for various applications. This is because Cerium reduces the material's ability to store electrical energy (lowers dielectric constant) without significantly increasing energy loss (keeps dielectric loss low, tan δ less than 1). The Jonscher power law is applied to model AC conductivity data indicating a non-ideal Debye relaxation process. DC electrical resistivity data are fitted by using small polaron hopping (SPH) and variable range hopping (VRH) model. Plots demonstrate the metal-semiconductor behaviour above room temperature of Ce-doped NdFeO3 samples. The PE loops highlight the ferroelectric properties of the material. [ABSTRACT FROM AUTHOR]

AC conductivity and dielectric relaxation of MoO3 doped V2O5–ZnO–CuO glass-nanocomposites have been studied in a wide temperature and frequency ranges. Electron microscopic studies reveal that Cu3O8V2 and Cu3Mo2O9 nanophases (for higher MoO3 content) have been developed, which are expected to form various defect states. Owing to formation of such nanophases, different values of maximum barrier height have been developed, which are supposed to play vital roles in the conduction process. Electric modulus formalism has been conceived as it can exclude the electrode polarization effect at low frequency regime and suggest the transition from long-range mobility to short-range mobility assembly of polarons. Correlated barrier hopping model and its modified version have been found to be most appropriate theoretical models to explore the conduction process. It is also noteworthy that relaxation times are found to increase with higher MoO3 content, which may indicate about the slow movement of charge carriers. The nature of variation of Kohlraush Williams Watts parameters can be considered as a tool to reveal the reason for shifting of relaxation process from Debye to Non-Debye type up to a limit with more and more incorporation of MoO3 content into the previous materials. By crossing the limiting value of composition (0.08 mol% of MoO3), it becomes non-Debye type at a very slow rate. Lower values of dielectric constant at high frequencies are expected to be important for their applications in photonics and opto-electronics. Scaling method of electric modulus spectra indicates that the dielectric relaxation process in the present system leads to a common relaxation process at various temperatures, but it is strongly dependent on compositions. [ABSTRACT FROM AUTHOR]

In the present work, Al-doped (0, 1, 2 and 3%) ZnO nanoparticles (NPs) are synthesised by green combustion method (GCM) using Terminalia Catappa seeds (TCS) extract as a novel fuel. For the synthesis Zinc nitrate and Aluminum nitrate are used as precursor and dopant respectively. The synthesised NPs are characterised by XRD, FTIR, UV-vi and impedance spectroscopy. The XRD analysis shows decrease in crystallite size varies between 40 to 26 nm as dopant increases. The FTIR spectrum reaffirms the formation of Zn-O bonding structure at 454.28 cm−1. UV-Vi spectroscopic studies show the optical band gap of 3.63, 3.53, 3.22 and 3.19 eV for Al doped (0, 1, 2 and 3%) ZnO NPs. Thermal analysis for the synthesised Al-doped (0, 1, 2 and 3%) ZnO nanoparticles are analysed using TGA/DTA studies. The Electrical characteristics are studied at various temperatures (50 to 350°C) by varying frequency (10 Hz to 8 MHz). In low frequency regions, dielectric constant and dielectric loss increases with rise in temperature. The constant AC conductivity is observed in lower frequencies and increases for higher frequencies for all doped ZnO NPs. ZnO NPs prepared with 2% of doping exhibit improved structural and electrical properties. Hence these ZnO NPs may be used as sensing material for vibration sensor. Highlights: This paper focus on green synthesis of undoped and Al-doped ZnO nanoparticles by combustion method. ZnO nanoparticles are synthesised using zinc nitrate precursor, Aluminium nitrate as dopant and Terminalia catappa seed extract as fuel. Effect of Al (0, 1,2 and 3%) doping on microstructural, optical, thermal and electrical properties of ZnO nanoparticles are investigated. The green synthesised doped and undoped ZnO nanoparticles exhibit hexagonal wruzite structure with high crystallinity. The FTIR spectrum reaffirms the formation of Zn-O bonding structure at 454.28 cm-1 The optical band gap is found to be 3.63, 3.53, 3.22 and 3.19 eV for 0, 1,2 and 3% of Al doped ZnO nanoparticles respectively. AC conductivity of ZnO nanoparticles is found to be increased with 2% of Al doped ZnO nanoparticles. Result shows an improved structural, optical and electrical performance for 2% Al doped ZnO nanoparticles and hence these nanoparticles are suitable material for sensors, organic light emitting diodes and liquid crystal displays. [ABSTRACT FROM AUTHOR]

Ferroelectric polymer-based separators, known for their flexibility, ease of synthesis, and modifiability through dopants, are currently under extensive study due its potential applications in electronic devices. PVDF nanocomposites, which combine the strengths of their constituents, currently lead in emerging technologies. This research employs Zinc oxide nanoparticles (ZnO NPs) as fillers in the PVDF matrix and investigates their structural, optical, thermal and electrical properties. ZnO NPs synthesized via the combustion method, are being incorporated with varying concentrations (2, 4, 6, 8, and 10 wt%), into PVDF nanocomposite (PNC) thin films through a solution casting process. The PNC thin films are characterized using XRD, FTIR, UV–Vis spectroscopy and thermogravimetric analysis (TGA). Dielectric properties are being explored across a frequency range from 20 to 2 MHz at room temperature, revealing enhanced dielectric constants at lower frequencies, decreasing with frequency due to Maxwell–Wagner interfacial polarization. With increasing frequency, AC conductivity and electric modulus exhibit enhancement. Complex impedance analysis via the Cole–Cole plot indicates a non-Debye type of dielectric relaxation with heightened conductivity. TGA demonstrates improved thermal stability in PNC thin films. These findings suggest the potential application of the prepared PNC thin films as separators in energy storage devices. [ABSTRACT FROM AUTHOR]

The organic–inorganic hybrid materials provide promising opportunities for use in optoelectronics due to its wide range of physical characteristics and structural configuration. In this study, a slow evaporation method at room temperature was employed to synthesize the new-centrosymmetric (C6H9N2)2[SbBr4]Br compound. Analyzing by X ray diffraction of the studied compound conferred a 0D framework with monoclinic structure. The examination of SEM analysis allows us to raise the morphology and the good quality of the crystals. The EDX analysis was performed to ensure that all chemical elements were discovered and located in the relevant locations. An optical absorption measurement confirms the nature of the material and his band gap. The differential scanning calorimetry (DSC) was performed at temperatures ranging from 313 to 413 K, with two heating cycles to isolate the effects of surface humidity and phase transition temperatures. Besides, the impedance spectroscopy measurements conducted at 10−1 Hz to 5 MHz and 313–403 K are used to investigate the electrical and dielectric properties of the (C6H9N2)2[SbBr4]Br compound. An equivalent circuit model has been proposed to correlate the electrical properties. The frequency-dependent ac conductivity was studied and helped to find the proper conduction model. [ABSTRACT FROM AUTHOR]

Abstract In this study, polymer composite nanofibers and thin membranes were synthesized using Carbon Nanotubes (CNTs) and Zinc Oxide (ZnO) as fillers in a Polyvinyl Alcohol (PVA) matrix, aiming to evaluate their electrical and mechanical properties. The composite nanofibers and thin membranes were prepared by incorporating different weight ratios of CNTs and ZnO into the PVA matrix using electrospinning and solution casting techniques, respectively. Solutions were prepared by mixing specific weight ratios of PVA, ZnO, and CNTs, followed by magnetic stirring and ultrasonication for homogenization. Electrospinning was performed at 20 kV with a syringe-to-collector distance of 14.5 cm at flow rate of 2.4 ml/hr. The composites were characterized using FTIR spectroscopy and Scanning Electron Microscopy (SEM). The PVA/5%ZnO/0.5%CNT composite exhibited the highest dielectric constant of 10.3 at high frequencies, while PVA/5%CNT showed the highest capacitance of 31.1 pF at 2 MHz. The maximum AC conductivity of 2.72 × 10− 7 S/m was also observed for the PVA/5%ZnO/0.5%CNT composite. Mechanical testing revealed significant improvements in Young’s modulus, stress yield, and load yield, with PVA/5%CNT achieving a Young’s modulus of 387.12 MPa and a stress yield of 6.92 MPa. The addition of ZnO and CNT fillers resulted in enhanced electrical and mechanical properties, making these composites suitable for applications in microelectronic devices and packaging materials.

High-voltage dielectric and AC conduction behaviors of epoxy resin (EP) insulation are beneficial for the design and application of solid-state power electronic devices. This study investigates the nonlinear dielectric response and AC conduction characteristics of EP. The dielectric relaxation characteristics, including permittivity and AC conductivity of the EP samples, were investigated using high-voltage dielectric spectroscopy and the ionic polarization model. The results demonstrate a nonlinear increase in the relative permittivity and AC conductivity concerning the AC electric field. The increase in AC conduction under a high-frequency electric field is attributed to the reduction in the threshold field for charge injection caused by elevated temperatures. Considering the dielectric response and carrier hopping, it is evident that the nonlinear dielectric response of EP primarily originates from the ionic process under high electric fields. Ionic polarization, in conjunction with ion-hopping conduction, enhances the dielectric loss at high frequencies and electric fields, thereby facilitating the nonlinear conversion of AC conduction. The equivalent free volume is likely to increase in high-frequency fields. This phenomenon leads to an increase in AC conduction and even dielectric breakdown. This study offers a pivotal theoretical framework for the design and application of high-frequency insulation. [ABSTRACT FROM AUTHOR]

A simple solution casting technique was used to formulate films of polyvinylidenefluoride‐co‐hexafluoropropylene, polymethylmethacrylate, and Ti3AlC2 MAX phase polymer nanocomposites (PPT) with different filler content. The functional groups present in the PPT films were studied using the Fourier transform infrared spectroscopy and the nature of crystallinity was observed using X‐ray diffraction technique. The morphology of the films was studied by scanning electron microscopy. The thermal analysis was done using the thermogravimetric analysis and differential thermogravimetry analysis. The tensile behavior of the prepared films was studied from the stress‐strain graphs. The ultraviolet–visible spectra revealed their optical characteristics. The dielectric parameters of the polymer blend and nanocomposite films like dielectric constant, loss tangent, AC conductivity, and complex impedance spectroscopy with corresponding equivalent circuits were studied. A comparative study of the above parameters was done for both the polymer blend and nanocomposites to find out the advancement in the properties of the prepared nanocomposite compared with the polymer blend. The nanocomposite film having 3 wt% of Ti3AlC2 MAX phase filler loading exhibited the best properties among all the nanocomposites. The enhanced dielectric properties of the nanocomposites with mechanical and thermal resistance can be used for real‐time efficient energy storage applications. [ABSTRACT FROM AUTHOR]

The goal of this work is to produce nanocomposites films for energy-storing and optoelectronic applications by incorporating ceramic nanofiller into a polymer blend. By using the one-pot hydrothermal process, manganese ferrite nanoparticles (MnFe 2 O 4 NPs) have been created. The produced NPs' size and morphology were verified by TEM, and the findings show that the particles are shape spherical and average size particles of around 21.45 nm. Using the casting approach, a series of polymer nanocomposites (PNCs) comprising carboxymethyl cellulose (CMC) and polyethylene oxide (PEO) have been created with various contents of MnFe 2 O 4 NPs: 2.0, 5.0, 8.0, and 12.0 wt%. The XRD results, which display the changes in PNCs' microcrystalline properties, revealed a decline in the samples' degree of crystallinity. FTIR spectroscopy has been used to verify that PNCs are properly formed and that functional groups are present in the nanocomposites. Using a UV–Vis spectrophotometer, the optical properties were examined. The absorbance coefficient was calculated for each sample. As the nanoparticle content increased, so did the E g decreased both direct and indirect of the PNCs. An increase in MnFe 2 O 4 loading improved the thermal characteristics of the nanocomposites, indicating enhanced thermal stability of the films due to nanoparticle-to-CMC/PEO blend interaction. The adding of MnFe 2 O 4 nanoparticles to the CMC/PEO matrix enhances the charge conduction mechanism, as seen by the doped samples' noticeably improved conductivity findings. As frequency increased, the dielectric loss (ε ″) and dielectric constant (ε ′) values decreased. The produced sample (8 % MnFe 2 O 4 /CMC/PEO) is the best option for energy-storing and optoelectronic applications like supercapacitors and sensors due to the structural changes and improvements made to the optical, thermal, and dielectric properties. [ABSTRACT FROM AUTHOR]

The flourishing environmental concerns have grabbed the attention of researchers developing environmentally supportive materials in various fields. A green approach was used to create biopolymer blend composites based on polyvinyl alcohol (PVA) and chitosan (CS) doped with various concentrations of grape seed (GS). Various analytical techniques, such as Fourier-transform infrared spectroscopy (FTIR), UV–visible (UV) spectra, field emission scanning electron microscope (FE-SEM) and differential scanning calorimetry (DSC) were used to evaluate the optical, structural and thermal properties of the prepared blend composites. The optical properties of blend composites were determined by UV spectroscopy and the findings revealed that absorption intensity increased with increasing GS, while bandgap energy decreased from 4.18 eV for pure blend to 2.91 eV for blend/15 wt% GS. The homogeneous distribution of GS particles in the biopolymer blend was identified with FE-SEM images. DSC results showed that increasing the GS content increased the glass transition temperature of the blend composites. The AC conductivity and dielectric constant were measured using the LCR meter. The conductivity rises with increasing frequency and dosage of GS, with the greatest conductivity obtained at 15 wt% loading. In comparison to a pure blend, it was discovered that the inclusion of 15 wt% GS enhanced the tensile strength by 50%, hardness by 17% and the reduction in elongation at break by 19 %. As a consequence, environmentally friendly PVA/CS/GS biopolymer blend composites with excellent mechanical, thermal, electrical, and dielectric parameters might be a viable green option for flexible electronic, electrochemical and energy storage devices. [ABSTRACT FROM AUTHOR]

Yttrium (Y) and cobalt (Co) co-doped bismuth ferrite (BFO) nanopowders were synthesized by the sol–gel method. The purity of the phase of the samples was confirmed by the X-ray diffraction technique. Both grains and grain boundaries contribute to the electrical response of the samples. The modulus studies show that the charge carriers can perform both long- and short-range mobility. Meanwhile, the Nyquist plot analysis confirms the samples' non-Debye-type relaxation behaviour and negative temperature coefficient resistance nature. The frequency-dependent AC conductivity obeys the power law A ω s at a higher frequency. AC conductivity increases from 1.300 × 10–5 to 8.463 × 10–4 S m–1, increasing Y and Co contents in the BFO sample. The temperature dependence of the AC conductivity suggests the presence of different conduction processes for all the samples. [ABSTRACT FROM AUTHOR]

Highlights In this electronic era, there is a demand to switch from conventional polymers to conducting biopolymers. We developed conducting biopolymer nanocomposites of cashew gum (CG) and polypyrrole (PPy) with zinc oxide (ZnO) nanofillers [CG/PPy/ZnO] via in‐situ oxidative polymerization using a sustainable solvent. These nanocomposites were characterized using Fourier‐transform infrared spectroscopy (FTIR), UV–visible spectroscopy, field emission scanning electron microscope (FE‐SEM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The FTIR signal at 855 cm−1 confirms the successful inclusion of ZnO nanofillers into the biopolymer. UV–vis absorption of the blend nanocomposite increases with the nanoparticle doses. Among the various blend nanocomposites, the least bandgap energy was observed for 7 wt% ZnO loading. FE‐SEM revealed homogeneous dispersion of ZnO nanofillers in the CG/PPy blend at 7 wt% ZnO. TGA and DSC demonstrated that the CG/PPy/ZnO nanocomposites have better thermal stability and glass transition temperature than the pure polymer blend, indicating enhanced thermal properties. The CG/PPy/7 wt% ZnO showed the highest conductivity, 4.62 times greater than the pristine blend at 100 Hz. Dielectric constant, activation energy, AC conductivity and dielectric loss measurements demonstrated that the nanocomposites outperformed the pure polymer blend. Complex impedance analysis revealed increased impedance with rising temperature. Overall, CG/PPy/ZnO nanocomposites exhibit superior optical, morphological, thermal, electrical, and dielectric properties, making them promising for energy storage and optoelectronic applications. Ecofriendly synthesis of CG/PPy/ZnO nanocomposites Enhancement in optical, structural, and thermal properties of CG/PPy/ZnO Dielectric properties and temperature‐dependent AC conductivity are summarized. Blend nanocomposite shows higher AC conductivity and dielectric constant CG/PPy/ZnO nanocomposites are suitable for energy storage applications [ABSTRACT FROM AUTHOR]

In this investigation, results of dielectric features of Li2O–Al2O3–SiO2 (LAS) glass doped with 3.0 mol% of Cr2O3, MoO3, and WO3 are presented. The investigation spans broad regions of frequency (ω) 10−2–106 Hz and temperature (T) 20–240 °C. Initial characterization of the samples by means of optical absorption spectra reveals that Cr ions do persist in Cr3+oxidation state, whereas fractions of Mo and W ions do present in Mo5+ and W5+ states in addition to predominant presence Mo6+ and W6 + ions, respectively. Infrared spectra suggest that Mo5+ and W5+ ions involve in modifying the network of the glass and induced structural disorder. Dielectric parameters and also σac are observed to be the largest for 40Li2O–5Al2O3–52SiO2:3.0 MoO3 (LASMo) glass followed by 40Li2O–5Al2O3–52SiO2:3.0 WO3 (LASW) and 40Li2O–5Al2O3–52SiO2:3.0 Cr2O3 (LASCr) glasses. Analysis of dipolar relaxation phenomena are carried out using Cole–Cole plots. Analysis of the results of σac suggests that polaronic conduction due to electron transfer between Mo5+ ↔ Mo6+ and W5+ ↔ W6+ is prevailed in case of LASMo and LASW glasses and these glasses are predicted to be useful as cathodes, whereas in LASCr glass, ionic conductivity is dominant and is suitable for electrolytes in ionic batteries. [ABSTRACT FROM AUTHOR]

The present study used ultra-sonication approach to manufacture ZnO/NiFe 2 O 4 (ZNF) and casting technique to prepare ZnO/NiFe 2 O 4 –Cs/PVP nanocomposite films. The successful creation of these nanocomposites with a significant decrease in the % crystallinity of the polymer blend with doping agent was verified by XRD results. ZNF and the Cs/PVP chains interacted in the polymer nanocomposites, as seen by the spectra of the FTIR. To determine the direct and indirect optical band gaps, tauc graphs were studied using data from UV–Vis analysis. The results indicate that while the Urbach energy was found to increase, the optical band gaps decreased as the weight percentage of the nanofiller increased. Using a thermogravimetric approach, the thermal stability of the produced PNCs has been investigated. Conductivity experiments demonstrated that when the nanofiller ZNF content increased to 2.5 wt%, so did AC conductivity, the dielectric loss, and the dielectric constant. The correlation between the mechanism of conduction and the amount of nanoparticles indicates that an increase in the percentage of ZNF in nanocomposites could increase their conductivity, with values ranging from 3.72 × 10−12 for pure blend to 7.72 × 10−8 S/cm for 2.5%ZNF-Cs/PVP at 100 Hz. The dielectric measurements for the nanocomposite films showed an increase in dielectric losses and dielectric constant, which is indicative of the films' enhanced dielectric polarization. The results of characterization point to possible uses of these polymer nanocomposites in flexible optoelectronic and magneto-electronic applications and energy storage devices. [ABSTRACT FROM AUTHOR]

This work investigates the AC conductivity, impedance spectroscopy, and modulus formulation of varied compositions of glass samples within the modified borovanadate glassy system, synthesized using the melt-quenching technique. Up to 10 mol% of BaO, the AC conductivity shows a rising trend as BaO content rises; however, for x = 15&20 mol%, there is a drop. The Almond West model fits the experimental data of ac conductivity and parameters such as crossover frequency, frequency exponent (s), and direct current conductivity are retrieved. All samples feature a CBH conduction mechanism at varying frequencies, except for VBa1, which has a small polaron quantum mechanical mechanism. There is good agreement in the activation energy derived from conductivity (0.565–0.742 eV), electric modulus (0.526–0.616 eV), and impedance research (0.530–0.743 eV). Dielectric studies reveal non-Debye-type behavior. According to impedance formalism, electric conduction occurs through Ba2+ ions and electron/polarons. This characteristic renders the glasses well-suited for energy storage devices. [ABSTRACT FROM AUTHOR]

Silicophosphate, prepared from Tunisian siliceous sand, has been investigated as a potential oxide ion conductor. XRD and Rietveld refinement analyses confirm the formation of pure single-phase Si5P6O25 that crystallizes in the trigonal system with R-3 space group. The electrical conductivities and dielectric properties of this material have been studied using complex impedance spectroscopy from 10 to 106 Hz at a temperature range from 600 to 680 °C. The results show that the ionic conductivity σdc increases from 5.43 × 10− 5 S.cm− 1 at 600 °C to 0.23 × 10− 3 S.cm− 1 at 680 °C with an activation energy of 1.33 eV. The frequency dependence of AC conductivity could be explained by Jonscher's power law. The dielectric constant's decrease with frequency indicates a region of dispersion resulting from a polarization process' relaxation. The simulation of the oxygen conduction using the Bond Valence Site Energy (BVSE) model shows the presence of four interstitial sites used with equilibrium sites to form a zigzag isosurface of oxygen migration. The calculated activation energy is about 1.43 eV. [ABSTRACT FROM AUTHOR]

Composite dielectric materials with different dielectric characteristics are crucial for energy storage devices. In this study, a composite material of 5 wt.% metal (M)/bentonite (Bento) (M = Cd, Cu, Fe, or Zn) was synthesized using a wet impregnation technique to examine the effect of metal incorporation in bentonite. X-ray diffraction, scanning electron microscopy, energy-dispersive x-ray analysis, and impedance analysis were carried out to investigate the structural, morphological, electrical, and dielectric properties of the samples. A low-frequency dielectric response provided evidence of dielectric relaxation, which was associated with local charge polarizations occurring at the grain (or particle) site. A reduction in the dielectric constant was observed in metal-doped composites, attributed to the variation in grain size and the resulting change in the dipole number per unit volume generated by doping. Interestingly, the AC conductivity dispersion decreased for dopants with a larger ionic radius, in line with qualitative expectations. Tight-binding calculations demonstrated that the changes in binding energy, hardness, and the positioning of the highest occupied molecular orbital and lowest unoccupied molecular orbital of Bento were responsible for the differences in dielectric properties resulting from the incorporation of different metals into Bento. Thus, our results demonstrate the successful metal doping-induced tunability of the dielectric and structural properties of Bento, with significant implications for its use as supercapacitor (optimal dopant is Fe, as it induces larger permittivity), and hence its polarizability. The lowest permittivity was achieved for Cd doping, suggesting its potential use for insulator applications. [ABSTRACT FROM AUTHOR]

The mechanically cleaved flake of ternary metal chalcogenide PbSnSe 2 was transferred onto the interdigitated electrodes to form electrical contacts. The temperature dependent (180 K–250 K) electrical properties were then analyzed employing complex impedance spectroscopy from 2 kHz to 2 MHz. A detailed analysis of Nyquist plots proposed the space charge dependent behavior and negative temperature coefficient of PbSnSe 2 flake. The AC conductivity followed Jonscher's power law with s -parameter value being less than unity. The values of s -parameter increased with rise in temperature suggesting the presence of non-overlapping small polaron tunneling (NSPT) in the PbSnSe 2 flake. From this NSPT model, tunneling distance, hopping energy, and density of states (DOS) were estimated at temperatures from 180 K–250 K. The dielectric permittivity showed dispersion at lower frequencies and the tangent loss was also found to be directly related to temperature. A single semicircular arc in complex modulus analysis showed the dominance of bulk effect in the material. [ABSTRACT FROM AUTHOR]

A glass series synthesized with composition (Na2O)x.(ZnO)10.(BaO)10.(B2O3)80-x as x=0-20mol% for the AC conductivity analysis concerning temperature and frequency. The incorporation of Na2O, results in enhancing AC conductivity up to two orders in both low frequency and high frequency. The Cole-Cole impedance plots exhibited semi-circles with a decrease in the radius, which reveals the decreasing bulk resistance values of the glass samples at higher temperatures. The results of AC conductivity and Cole-Cole plots were matched with the nearest AC conduction values. The FT-IR spectrum confirmed the role and structural variations of network modifiers due to the addition of Na2O. The optical spectroscopy resulted in an increase in cut-off, a decrease in band gaps, an increase in refractive index, and Urbach energy. The density increased & molar volume decreased with Na2O content. The higher order conductivity (10-3 ohm-1 cm-1) confirms the suitability of the glasses for battery and solid-state electrolytes. [ABSTRACT FROM AUTHOR]

In this work, perovskite oxide SrCeO3 was synthesized using the solution combustion method (SCM). Synthesized samples have been characterized using X‐ray diffraction (XRD), Raman, ultra violet (UV)–visible spectroscopy, and scanning electron microscopy (SEM) techniques. The XRD and Rietveld refinement has confirmed the orthorhombic structure with space group Pnma. The average grain size of this ceramic sample is 1.2 µm. The dielectric constant, dissipation factor, modulus, impedance, and alternating current (AC) and direct current (DC) conductivities were analyzed in the temperature range RT to 600°C and frequency range 20 Hz–2 MHz. Further, it was observed that the role of grain boundaries in dielectric and electrical properties is significant, at low temperatures. The origin of the dielectric relaxation and conduction process is the same. The activation energy for DC conduction (Edc) was found to be.79 eV. Electrical conduction/relaxation is assigned to the diffusion of doubly ionized oxygen (Vo··). The value of DC conductivity (1.2 × 10−3 Ω−1 cm−1 at 600°C) and activation energy of.79 eV is very close to the values reported for doped CeO2‐based oxide ion conductors for SOFCs. This study has demonstrated that SrCeO3 can be an alternative candidate for the oxide ion conductor electrolyte application and the potential to be used as a thermally stable capacitor application for microwave dielectric applications. [ABSTRACT FROM AUTHOR]

BaBiLaNbVO9 is a lead-free compound and has been synthesized by solid-state technique. The formation of the compound was confirmed by X-ray diffraction and is found to be crystallized in the monoclinic (space group P 21) crystal system (a = 13.7464± 0.0015 Å, b = 4.0156± 0.0012 Å, c = 12.4946 ± 0.0018 Å, β = 93.48 ± 0.01o). The crystallite size was found to be 52.91 nm. SEM and EDX studies analyzed the morphology, composition, and elemental distribution in the specimen. The average grain size is about 1.0651 μm. Several properties, such as frequency and temperature response resistivity, conductivity, and dielectric behaviours of the compound, have been analyzed. The overlapping large polaron tunnelling (OLPT) and correlated barrier hopping (CBH) models are appropriate for electrical conduction in the compound. The energy band gap (Eg) of the material was 2.40 eV, suitable for optoelectronic devices. Ferroelectric behaviour may be deduced from symmetric and well-shaped P-E hysteresis loops. The impedance study satisfies the negative temperature coefficient of resistance (NTCR) behaviour, which is suitable for thermistor devices and its correlated application. [ABSTRACT FROM AUTHOR]

A microscopic study of the large or dielectric polaron behaviour has been carried out for the first time for MgFe2O4. We have considered a new methodology to study in depth the Overlap Large Polaron Tunneling (OLPT) conduction mechanism in a large temperature range. This methodology consists in extracting theory from experimental data. Unexpected and even spectacular results are determined. However, to the best of our knowledge, it is for the first time, that we prove the existence of the magnetic polaron in MgFe2O4 in the ferromagnetic phase as an alternative to the dielectric one. The function added to the trapping potential shows a competitive behavior between the magnetic effect and the crystal lattice acoustic vibration. Our theoretical model can be generalized for ferrite materials exhibiting the (OLPT) conduction mechanism. Indeed, this model allows checking the existence or not of the magnetic polaron, to determine its radius, the magnetic correlation length variation with frequency, the formation temperature of the magnetic polaron (TM) and other features sometimes inaccessible even experimentally. [ABSTRACT FROM AUTHOR]

Monoclinic β-Ga2O3 thin films were grown on heavily doped p-type Si substrate by pulsed laser deposition (PLD) at growth temperature 700 °C and oxygen partial pressure 1 × 10–2 torr to determine its ac electrical behavior with frequency at different elevated temperatures for its possible harsh environment applications. X-ray diffraction (XRD) and X-ray photoelectron (XPS) spectra reveals a randomly orientated polycrystalline monoclinic β-Ga2O3 phase with all possible chemical states of Ga and O. The electrical characteristics including impedance, dielectric and conductivity of β-Ga2O3/Si (100) heterostructures were performed by impedance analyzer in the frequency domain 100 Hz–1 MHz and temperature from 25 to 400 °C. Three different resistor–capacitor (RC) circuit in series were identified in the Nyquist plots (Zʹʹ vs. Zʹ) which corresponds to the β-Ga2O3 film, Si substrate and interfacial barrier effect and their contributions gradually compensating with temperature. The real electrical permittivity ( ε r ′ ) increases with temperature from ~ 5.35 (25 °C) to ~ 293.8 (400 °C) and exhibits a Maxwell–Wagner type electrical polarizations based on Koop's phenomenological theory. The radius and contributions of Cole–Cole plots of dielectric diminished with temperature due to temperature dependent relaxation processes. The oxygen vacancies induced the enhanced electron donor sites in β-Ga2O3 and the activation energy (Ea) for ac electrical conduction for β-Ga2O3 and Si was estimated to be ~ 0.87 eV and 0.07 eV, respectively. The variation of frequency exponents n1 and n2 with temperature revealed two different conduction mechanisms- (i) quantum mechanical model (QMT) for Si (100) substrate, and (ii) non-overlapping small polaron tunneling conduction model for β-Ga2O3. [ABSTRACT FROM AUTHOR]

In this study, gadolinium (Gd) and chromium (Cr) co-doped yttrium iron garnet (Y3Fe5O12) nanoparticles were prepared by the sol–gel method. The X-ray diffraction (XRD) data, which was further refined by Rietveld analysis, proved the cubic (Ia-3d) structure without any secondary phase. Surface morphology and microstructure analysis were investigated utilizing field emission scanning electron microscopy (FESEM). FESEM images show how dopants (both Gd and Cr) particles have dispersed non-uniformly in the Y3Fe5O12 matrix and the nanostructured particles with size range from 97 to 284 nm for different Gd and Cr levels. Ferroelectric measurements present a substantial improvement in polarization under a saturated applied field of ± 5 kV/cm for doped, and co-doped Y3Fe5O12. At room temperature magnetic properties are measured by VSM, and it is found that the magnetic properties (saturation and remnant magnetization) are reduced (enhanced) with Gd3+ (Cr3+) doping substantially. UV–VIS spectrophotometry revealed a significant reduction in optical band gap energy from 2.23 to 1.99 eV due to Gd and Cr co-doping in Y3Fe5O12. The dielectric behavior of Y3Fe5O12 is studied in the 100 Hz to 1 MHz frequency range. The frequency-dependent dielectric constant displays the normal dielectric dispersion response, which is explained in terms of polarization concentration using Maxwell–Wagner theory. The dielectric constant is independent of the frequency at longer wavelengths (˃ 105 Hz), owing to only ionic and electronic polarizations. The AC conductivity (σAC) complies with the power law, and the linearity of log2 versus logσAC plot shows that the conduction mechanism is due to limited polar hopping. The obtained results anticipated that Gd3+- and Cr3+-doped Y3Fe5O12 exhibit improved properties for application compared to pure Y3Fe5O12. The synthesized ceramics may find potential applications in sensors, capacitors, actuators, transducers, and memory devices. [ABSTRACT FROM AUTHOR]

Using the solution cast method, researchers prepared Poly(vinylidene fluoride) (PVDF)/Poly(ethylene oxide) (PEO) blend doped with various weight ratios of Cobalt oxide nanoparticles (Co3O4 NPs). XRD analysis revealed a remarkable increase in the amorphous nature of the nanocomposites as the Co3O4 concentration climbed. The Notable alterations were revealed by the FT-IR spectra, revealing interactions between the PVDF/PEO blend and Co3O4 NPs. We found a significant red shift in the fundamental absorption edge of nanocomposites films using UV–visible spectroscopy. As the concentration of Co3O4 ions rose, the direct bandgap of PVDF/PEO film decreased significantly, from 5.39 eV to 3.96 eV, while the Urbach energy increased. Thermal analysis in the range of 30–500 °C revealed a remarkable improvement in the thermal stability of the nanocomposites compared to their pure PVDF/PEO blend. The endothermic melting temperature (Tm) of the PVDF/PEO blend is 130 °C was calculated from DSC analysis. To delve into the electrical behavior of the films, its conductivity was examined using an AC impedance analyzer over a broad frequency range of 100 Hz–7 MHz at room temperature. As the Co3O4 NP content ramped up and the frequency climbed, the material's electrical conductivity responded in kind, showing a consistent upward trend. The electrical conductivity of the nanocomposite films, as a function of frequency, neatly follows Jonscher's equation. The PVDF/PEO blend containing 2%Co3O4 NPs reigned supreme in terms of ionic conductivity, boasting a remarkable 6.5 × 10–4 Scm−1 at room temperature. The dielectric constant increases with Co3O4 concentration, according to dielectric permittivity studies, because of interfacial polarization at the PVDF/PEO and Co3O4 interfaces. The findings show that the films made from nanocomposites have improved optical, thermal, electrical, and dielectric properties. The gathered data suggests that the Co3O4 nanoparticles doped PVDF/PEO mix films are a novel, easy-to-work-with, and promising material for a range of applications, such as optoelectronics, electronics, and other flexible energy storage devices. [ABSTRACT FROM AUTHOR]

In this paper, the electrical conductivity characteristic of polyaniline (PANI) coated CuO nanocomposites of different wt% of CuO nanoparticles can be studied. The synthesis of PANI/CuO nanocomposites was done by in-situ chemical polymerization reaction. Spectroscopic characterizations were done using FTIR, SEM, TGA, XRD, and UV-Vis techniques. The presence of functional groups, surface morphology, and semi-crystalline nature of the sample can be confirmed by FTIR, SEM, and XRD studies. High thermal stability of the sample was confirmed by TGA studies. The frequency-dependent AC conductivity and dielectric attributes of nanocomposites studied at normal room temperature showed tunability with varying wt% of CuO indicating PANI/CuO (5%) exhibits high AC conductivity and dielectric constant values than (10% &15%). It can be observed that the presence of CuO in PANI affects EMI shielding. The synthesized nanocomposites showed excellent EMI Shielding effectiveness of -18.2 dB to -23.1 dB. The results indicate PANI/CuO nanocomposites utilized as potential shielding materials in X-Band. Also, the PANI/CuO/GC electrode expresses good sensing performance for Dopamine. Further PANI/CuO/GCE shows excellent long linear range, sensitivity, and LOD are 10 to 180 µmol/L, 0.0153 and 3.666 and R² is 0.9951. Also, this sensor shows repeatability and stability without leaching property. [ABSTRACT FROM AUTHOR]

Aluminum oxide nanoparticles (Al2O3 NPs) were added to polyvinylpyrrolidone (PVP) and sodium alginate (SA) blend to synthesis nanocomposite films, using a solution casting technique, with favorable optical and electrical properties. The results reveal a series of noteworthy findings, where X-ray diffraction (XRD) measurement also shows that the addition of Al2O3 NPs to PVP/SA blend caused a decrease in the crystallinity of the filled samples. Fourier infrared (FTIR) analysis showed prominent characteristic peaks corresponding to vibrational groups characterizing the prepared nanocomposite samples, which change randomly with increasing concentration of Al2O3 NPs. Moreover, the indirect/direct optical energy gap decreased from 3.96/5.28 to 2.73/3.59 eV at 2.0 wt% of Al2O3 NPs, confirming the improvement in the optical features of the doped samples, as evidenced by UV/Vis spectra. After adding the nanoparticles to the blend, AC electrical conductivity increased and showed to follows Jonscher's rule. The maximum value of AC conductivity observed at 2.0 wt% of Al2O3 NPs in the blend is 1.445 10− 6 S/cm. Additionally, the addition of the nanoparticles has been shown to increase in dielectric loss and dielectric constant of the composite samples. The improvement of the optical and electrical properties due to filling with Al2O3 NPs indicates the possibility of using the prepared nanocomposites in optoelectronic devices. Also, studying the effect of incorporating Al2O3 nanoparticles into PVP/SA blends has attracted little attention in the literature; therefore, this study is considered as a new research one. [ABSTRACT FROM AUTHOR]

Polyvinyl chloride (PVC) and polymethyl methacrylate (PMMA) have been used as polymeric matrices for the synthesis of polymeric nanocomposite films that incorporate titanium oxide nanoparticles (TiO 2 NPs) and graphite nanoplatelets (GNPs) as nanofillers. Based on TEM studies, TiO 2 nanoparticles have a tetragonal anatase phase, ranging in size from 15 to 60 nm, whereas GNPs have a nanoplatelet-like shape, varying in thickness from 10 to 20 nm. XRD analysis shows that PVC/PMMA polymer nanocomposite samples have less crystallinity when added with TiO 2 NPs and GNPs. Infrared Fourier analysis (FT-IR) indicated a complex interaction between the PVC/PMMA blend and both GNPs and TiO 2 NPs. The UV/visible spectrum of the PVC/PMMA blend showed two absorbance peaks at 279 and 223 nm which may result from the n→π* and π→π* transitions. Moreover, optical bandgaps were reduced for both indirect and direct transitions when TiO 2 NPs and GNPs were added. AC electrical conductivity and dielectric properties of the samples were measured at room temperature. Results indicated a significant increase in conductivity after filling from 2.6 x 10−14 S/cm for pure PVC/PMMA to 7.3 x 10−6 S/cm for PVC/PMMA-TiO 2 /GNPs nanocomposite. In addition, high nanoparticle concentrations lead to higher composite dielectric loss and dielectric constants. These findings suggest the possibility of using the prepared nanocomposites in capacitive energy storage and optoelectronic devices. [ABSTRACT FROM AUTHOR]

The ceramic compound CuFe2O4 was synthesised via conventional high-temperature solid-state reaction route. The structural study of the compound was done using X-ray diffraction technique. The preliminary structural study was performed using POWD software and a tetragonal structure was suggested. The Rietveld refinement of XRD (X-ray Diffraction) data was carried out using FullProf software and the refined lattice parameters were obtained as a = 5.80030 Å and c = 8.69400 Å with high tetragonality ratio. The crystallite size and lattice strain were calculated using Williamson–Hall (W-H) plot. The temperature and frequency dependent electrical properties of this compound are analysed using complex impedance technique. The impedance and modulus study of the compound showed the contribution of intra-grain effect to the overall electrical response. The studied ceramic possessed a non-Debye-type relaxation mechanism. The bulk resistance decreased with the increase in temperature, thus showing negative temperature coefficient of resistance behaviour. Modulus and conductivity study showed the evidence of conduction via hopping mechanism inside the material. Frequency-dependent AC conductivity followed Jonscher's universal power law. The Arrhenius equation was fitted with the temperature-dependent AC conductivity at different frequencies, and activation energies were determined to understand the charge species involved in the conduction mechanism. [ABSTRACT FROM AUTHOR]

Bitumen with 50/70 penetration was prepared and modified by doping with the unsaturated polyester resin based on isophthalic acid at 5% by weight (w/w%). The structural, mechanical, and thermal properties of bitumen and bitumen modified with unsaturated polyester resin %5 (UPR) were determined. The dielectric properties of bitumen and modified bitumen were investigated in the frequency and temperature ranges of 0.1-106 Hz and (-)40°C- 40°C, respectively. Polarization mechanisms, glass-transition temperature, and ductility of all samples were determined and compared to each other. The glass transition temperature of the modified bitumen shifts toward low temperatures in comparison to the bitumen. So, it can be suggested that the use of modified bitumen is very attractive in regions where the temperature differences are high. Also, the dielectric analysis method is an innovative alternative to determining modified bitumen's low-temperature performance. It was found that the modification with UPR provide strength and flexibility to asphalt. [ABSTRACT FROM AUTHOR]

This work reports the structural, thermal, optical and electrical properties of PEMA, PVC and their polyblends. These properties are investigated by FTIR, TGA, UV/Vis and broadband dielectric spectroscopy. FTIR spectra showed that the characteristic bands of PEMA and PVC are affected by blending and displayed red and blue shifts confirming that an intermolecular interaction between PEMA and PVC is occurred. Thermal degradation kinetics of PEMA, PVC and its polyblend samples is investigated in details and the thermal properties of each decomposition stage are estimated. UV measurements analysis revealed that Urbach energy (EU) is increased while optical bandgap decreased upon increasing the PVC content. The indirect and direct band gap (Eig/Edg) values are decreased from (3.95/4.21) to (3.10/3.92) eV. Also, upon increasing the content of PVC, the lattice dielectric constant (εL) is increased from 2.71 to 7.83. Wemple-DiDomenico model is applied for investigating the refractive index dispersion and to calculate the oscillator and dispersion energies. It is observed that the linear/nonlinear parameters are increased nonlinearly with increasing the PVC content. χ(1), χ(3) and n2 values are found to increase from 0.104, 0.213 × 10−13 and 4.01 × 10−12 to 0.363, 31.26 × 10−13 and 5.33 × 10−12. These results make PEMA/PVC polyblend strong candidates for use in the development and design of advanced optoelectronic devices. AC conductivity (σac) and dielectric measurements are carried out at various temperatures in wide frequency range. Jonscher power law is applied and showed that the predominant conduction mechanism in our samples is overlapping large-polaron tunneling (OLPT). The dielectric constant and electrical impedance are found to be frequency and temperature dependent. The investigation of the electric modulus (M*) revealed that M′ is increased non-linearly with increasing the frequency, while M″ spectra displayed two different modes of relaxation. The interfacial polarization (IP) is observed in low frequency region, while, dipolar relaxation is detected in high frequency region.

This study investigates the structural, dielectric, optical, and electrical properties of eco-friendly polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) matrices embedded with zinc manganite nanoparticles (ZnMn2O4NPs). The nanocomposites films were prepared using a casting method for potential applications in flexible electrochemical devices. FTIR spectroscopy confirmed the successful incorporation of ZnMn2O4NPs into the polymeric matrix. UV–Vis absorption analysis revealed an increase in absorbance with increasing ZnMn2O4 nanoparticle content. Among the various blend nanocomposites, the lowest bandgap energy was observed for the sample containing 2.5 %ZnMn2O4 NPs. Measurements of electrical conductivity, dielectric characteristics, and complex impedance were made for all prepared films. The findings showed that as frequency and nanofiller concentration increased, so did AC conductivity and dielectric characteristics. Overall, the PVA/PVP-2.5 % ZnMn2O4 nanocomposite exhibited superior properties compared to the pure polymer blend. This sample demonstrated optimal electrical conductivity and dielectric constant. These findings suggest that by carefully adjusting the ZnMn2O4 concentration, it is possible to fine-tune the dielectric, optical, and electrical properties of these nanocomposite films. This versatility offers promising potential for applications in optoelectronic devices, energy storage devices, and nanodielectric materials.

In the present work, pure TiO2 and Fluorine doped TiO2 (F–TiO2) thin films were prepared and their effect on the photovoltaic response of perovskite solar cells was investigated. Six samples of Fluorine doping of 0, 2, 4, 6, 8, and 10 at. % were prepared using the spin coating method. The F–TiO2 thin films were analyzed using various characterization techniques, including XRD, SEM, and LCR impedance measurements, to ascertain their structural properties, surface morphology, A.C. conductivity, and dielectric constant. The perovskite solar cells were prepared using F–TiO2 as an electron transport layer, MAPbI3 perovskite as the light absorber layer and NiO as the hole transport layer. Further, the DFT calculations were performed using F–TiO2 and perovskite molecules to investigate the electronic properties of the system. The XRD results indicated the formation of the anatase phase of the TiO2. Images obtained by SEM show the multilayer deposition in perovskite solar cells. Both the experimental and computational analysis suggest that the photovoltaic response of the F– TiO2 perovskite solar cell samples was much more impressive than that of the un-adulterated samples.

The glass of composition 60Bi 2 O 3 –10SrO–30Fe 2 O 3 (BSFO) (in mol%) was prepared by conventional melt quenching technique. Heat treatment process was applied to the glass samples at temperature close to crystallization temperature (600 °C) for different time intervals of 0, 2, 4 and 8, respectively, to obtain glass ceramic nano-composites. X-ray diffraction (XRD) patterns displayed the formation of a cubic Bi 3.43 Fe 0.57 O 6 for BSFO glass-ceramic nano-composites. The average nanocrystallite size (D) was determined to be between 13.48 and 17.26 nm. The values of D of the present samples were increased with an increment of heat treatment time. The high resolution-transmission electron microscope (HRTEM) images of a BSFO glass sample that was heat treated at 600 °C for 4 h show the nanocrystallites dispersed in the glass matrix with particle size in the range of 17 nm. The real part of permittivity (ε′) of BSFO decreased sharply with the increment in frequency for all samples. The decrement in the magnitude of the real part of impedance (Z′) with the increment in both frequency and temperature suggests an increase in ac conductivity σ ac. The correlated barrier hopping (CBH) model can explain the exponent S and temperature behavior we observed throughout all samples. For all glass–ceramic nano-composites, with an increase in the electric field, remnant polarization P r increases. This confirms its ferroelectric nature. The energy storage density (W r) is found to be maximum for the HT 8 h sample and equal to 34.3 mJ/cm3. The efficiency (η) of the HT 8 h sample was 65 %. The (M − H) loops of the glass–ceramic nano-composites displayed an antiferromagnetic trend. These observations suggest that the present samples might be a promising option for producing energy storage devices. [ABSTRACT FROM AUTHOR]

Hexaferrites, with their exceptional crystalline anisotropy, substantial coercivity, tuneable cations, and high magnetic hardness, are crucial as permanent magnets in applications such as information storage, sensors, high-frequency and microwave-absorbing devices. In this study, the focus was on synthesizing copper and cadmium-substituted strontium W-type hexagonal ferrites (SrCu 2-x Cd x Fe 16 O 27) with varying x values of 0.00, 0.01, 0.02, 0.03, and 0.04. To comprehensively investigate their structural, morphological and optical characteristics, several analytical techniques were employed, including XRD, SEM, FT-IR spectroscopy and UV–Vis spectroscopy along with dielectric and magnetic techniques. The XRD analysis showed a minimum crystallite size of 13 nm for x = 0.0 and a maximum of 21 nm for x = 0.04. The morphology was examined through SEM, affirming the characteristic structure of W-type hexaferrites. FT-IR spectra exhibited two prominent peaks at 491 cm−1 and 890 cm−1, further validating the creation of W-type hexaferrites. Notably, the UV–Vis spectroscopy demonstrated a reduction in the optical band gap from 2.41 to 2.11 eV with increasing concentrations. In terms of dielectric properties, a peak dielectric constant of 71 was observed at frequencies above 2.5 GHz. Furthermore, the AC conductivity displayed a linear trend at lower frequencies, reaching a maximum value of 0.35 [ohm cm]−1 at higher frequencies. The magnetic measurements indicated that the substitution of x = 0.04 exhibited the highest saturation magnetization, Ms value of 1.7 emu/g, but the lowest coercivity, Hc value of 75 Oe was observed. [ABSTRACT FROM AUTHOR]