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In the present study, NdFeO3 (NFO), Nd(0.9)Ba(0.1)FeO3 (NBFO), NdFe(0.9)Mn(0.1)O3 (NFMO) and Nd(0.9)Ba(0.1)Fe(0.9)Mn(0.1)O3 (NBFMO) were successfully synthesized using citrate sol–gel chemical route. X-ray diffraction (XRD) patterns confirm the formation of orthorhombic perovskite structure with space group Pbnm and are further complemented by the Rietveld refinement. Scherrer's formula as well as Williamson–Hall (W–H) plot was used to calculate average crystallite size of the prepared samples. Further, morphological investigations were carried out using SEM imaging and EDX spectroscopy. Dielectric properties including frequency dependence of dielectric permittivity (ε), tangent loss (tan δ) and electrical conductivity (σ) of all the samples were analysed at different temperature ranges from 300 to 623 K over a frequency range from 100 Hz to 1 MHz. It was found that the ε decreases with the increase in frequency. Optical properties were investigated using the UV–visible spectroscopy and the Tauc's plot was employed on the absorbance spectra for calculating the energy band gap. It was found that the band gap decreases as the dopants are inserted in the lattice of NFO. Magneto-dielectric properties were analysed by using varying magnetic field from 0 to 2 T. These samples could serve as the properties of materials with potential applications in logic gate, data storage, switches and sensors. [ABSTRACT FROM AUTHOR]

This study employed sol–gel technique to synthesize CuOx-ZnO1-x nanocomposites with varying concentrations of CuO (x = 0, 0.25, 0.50, 0.75 and 1.00). The resulting samples were analysed using X-ray diffraction (XRD) to confirm the presence of hexagonal wurtzite ZnO and monoclinic CuO phases. Scherrer's formula and W–H plot were used to determine crystallite size and microstrain, revealing a reduction in crystallite size from 37 to 23 nm with increasing CuO concentration. Optical analysis showed a visible spectrum absorbance and a decreasing optical band gap from 3.25 to 1.54 eV with higher CuO concentrations, impacting photovoltaic and optoelectronic applications. Dielectric studies demonstrated Maxwell–Wagner interfacial polarization across a frequency range (100 Hz–1 MHz) and temperatures (303–573 K), while AC conductivity exhibited low-frequency dispersion revealing enhanced properties with CuO addition. Overall, this study provides valuable insights into CuO-induced modifications in ZnO nanostructures, informing the design of materials with enhanced optical and electrical properties for advanced optoelectronic technologies. [ABSTRACT FROM AUTHOR]

A graphene quantum dot (GQD)-decorated ZnFe2O4 hybrid nanocomposite [GQD-ZHN] was synthesized using the sol–gel technique. In the X-ray diffraction (XRD) analysis, a cubic spinel structure was identified with the space group Fd-3 m. Fourier-transform infrared (FT-IR) analysis revealed the vibration bands of the samples, while the existence of GQDs in GQD-ZHN was confirmed by the Raman spectra. Field emission scanning electron microscopy (FESEM) provided insights into the microstructural morphological topology of the surface. The dielectric properties of GQD-ZHN were analysed with respect to their dependence on frequency and temperature and explained by Maxwell–Wagner-type polarization. The frequency-dependent ac conductivity (σac) followed Jonscher's power law and investigated the dynamics of ion hopping in GQD-ZHN. Impedance and modulus spectroscopy were used to further evaluate electrical characteristics such as relaxation time (τ). Nyquist plots have been used to estimate grain and grain boundary contributions. The GQD-ZHN exhibited superparamagnetic properties at room temperature. At room temperature, GQD-ZHN exhibited a strong magneto-dielectric coupling (MD) and showed negative magneto-dielectric properties in low-frequency regions. These properties of GQD-ZHN enable it to be used as a potential application in microelectronic systems, spintronics and memory devices. [ABSTRACT FROM AUTHOR]

CaCu3Ti4O12 (CCTO), LaFeO3 (LFO) and YFe0.5Cr0.5O3 (YFCO) were synthesized via conventional sol–gel auto–combustion method using citric acid as gelling agent. The X‐ray diffraction analysis revealed the phase purity of the samples. The energy dispersive X‐ray (EDX) analysis confirms the stoichiometry of the pristine phases. The average particle size obtained from the field emission Scanning electron microscopy (FE−SEM) images revealed that CaCu3Ti4O12 exhibits a broad range of particle size starting from a couple of hundreds of nanometer to micrometer, whereas that for LaFeO3 and YFe0.5Cr0.5O3 are about 110 nm and 50 nm, respectively. We have fabricated the new composites: CCTO–LFO, CCTO–YFCO and LFO–YFCO. The grain sizes of the composite phases are consistent with the pristine phases as they are prepared by at lower sintering temperatures and duration. The dielectric properties of these ceramic composites were compared to those of the pristine phases. The temperature and frequency dependent dielectric measurements reveal a wide range of dielectric constant with moderate tan δ values. The temperature dependent dielectric constant of the investigated samples varies from 100 to 1500 at room temperature and the data have been analyzed using universal dielectric response (UDR) model. [ABSTRACT FROM AUTHOR]

CaCu3Ti4O12 (CCTO) nanomaterials were synthesized using the low-cost facile sol-gel technique. X-ray diffraction (XRD) patterns confirmed the cubic structure of the prepared sample. Scherrer's formula and the W-H (Williamson-Hall) plot was used to calculated the average crystallite size of the prepared sample and it was found to be 27 nm and 31.3 nm, respectively, while the strain created in the lattice is 5.008 × 10−4. Based on the absorbance plot, the band-gap (Eg) of the sample was determined using Tauc's plot and it was found out to be 2.74 eV. The frequency dependence of dielectric permittivity (ε) and tangent loss (tan δ) of CCTO was analyzed at different temperature range from 300 K to 663 K over a frequency range from 10 Hz to 1 MHz. ε and tan δ decrease monotonically in entire frequency range and an anomalous frequency-dependent behavior was observed at different temperatures. High ε (in the range of 104) was found out at lower frequency range. Electrical conductivity was also analyzed in range of frequencies and temperature, it was found out that in higher region of frequency conductivity slightly increases. The room temperature values of ε, tanδ and conductivity was 7.5 × 103, 1.5 and 0.4 × 10−5 Ω−1 m−1, respectively. The reduction in Eg is achieved which was the major concern in this work. Furthermore, we have extensively studied the ε along with tan δ and ac conductivity for electronic application usage. According to these observations, CCTO is particularly prepared so that it could be suitable for microelectronic applications due to its high ε and low tan δ. [ABSTRACT FROM AUTHOR]

Carbon quantum dots doped ZnFe2O4 Spinel Ferrite, that is, CQD-ZSF hybrid nanocomposite was thrivingly synthesised exploiting sol-gel based synthesis technique. Structural assessment supports Fd-3m space group with cubic spinel structure with mean size of 10.33 nm as obtained from Scherrer formula. Raman spectra confirmed the existence of CQD in ZSF. The samples contained a variety of vibration bands, according to the FT-IR analysis. The dielectric permittivity (ε) and tangent losses (tan δ) was conducted with frequency from 100 Hz to 1 MHz range at different temperatures ranging from 300 to 773 K. It was found that ε as well as tan δ receded monotonously with extending frequency. This information reveals a space or interfacial dipolar relaxation phenomenon. The electrical properties and the ion hopping dynamics were probed with the assistance of an AC-electrical conductivity (σac) analysis. Frequency-dependent σac heeded Jonscher's law of power. The advent of arcs semicircular by nature in cole-cole plot indicates cloud of electronic process occurring within sample. At 300 K, by applying an external magnetic field varying till 1.5 Tesla magnetic field, the magneto-dielectric effects of the sample were measured by obtaining ε and tan δ versus frequency values displaying negative ML% (magneto-loss) and MD% (magneto-dielectric) coupling of −32.57% and −58.13%, respectively. [ABSTRACT FROM AUTHOR]

Solid polymer electrolyte films blended with ionic liquid 1‐ethyl‐3‐methylimidazolium tricyanomethanide (EMImTCM) and poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVdF‐HFP) are prepared via solution cast technique. The physical characterization of polymeric film is performed by X‐ray diffraction (XRD), polarized optical microscopy (POM), Fourier transform infrared spectroscopy (FTIR), and thermo‐gravimetric analysis (TGA) studies. The gel electrolyte film with 300 wt% of IL shows the high ionic conductivity value of 3.7 × 10−2 S cm−1, and operating voltage from −0.5 to 1.5 V, i.e., electrochemical stability window (ESW) ≈ 2.0 V. The dielectric properties of the polymeric films such as dielectric constant, dielectric loss tangent (Tan δ), relaxation frequency, and time are evaluated. [ABSTRACT FROM AUTHOR]

0.9Bi1-xNdxFeO3 − 0.1PbTiO3 solid solution with x = 0.05, 0.10, 0.15 and 0.20 were success fully synthesized by the standard solid-state reaction method. The effect of Nd3+ion substitution on structural, micro structural, ferroelectric, magnetic and dielectric properties of 0.9BiFeO3-0.1PbTiO3 have been investigated. The XRD analysis for the samples under study revealed distorted rhombohedral structure with R3C space group. 0.9Bi1-xNdxFeO3 − 0.1PbTiO3 i.e. (BNFPT)x with x = 0.05, 0.10, 0.15 and 0.20 compounds crystallized as single-phase materials with the same structure as the parent BiFeO3 compound. The SEM study revealed the uniform grain scattering for all prepared samples. Raman spectroscopy showed disappearance of some Raman modes indicated a structural phase transition with substitution of Nd dopants at Bi site and also confirmed the distorted rhombohedral perovskite structure of (BNFPT)x compounds with R3c symmetry. Dielectric measurements reveals that, around Neel temperature, all the samples exhibit magneto-electric coupling and also improved dielectric properties with addition of dopants in BiFeO3(BFO) compound. All the prepared samples exhibit weak ferro-magnetic character at room temperature. However, the variation in linear behavior and enhancement in magnetization is found at 5 K which shows gradual increase in remnant magnetization from 0.00785 emu/g to 0.37513 emu/g with increase in Nd doping for all (BNFPT)x samples. Nd doping reduces leakage current by three orders of magnitude, from 10−4 to 10−7. Ferroelectric study revealed the pinning effect in hysteresis loops with low remnant polarization and coercive field which can be related to the energy storage performance of the samples. [ABSTRACT FROM AUTHOR]

The present paper reports the preparation and characterization of ionic liquid immobilized quasi-solid-state electrolytes (QS-SEs) "PEO-LiPF6-ionic liquid (IL)" with polymer PEO, dopant salt (LiPF6) and ionic liquid, BMIMPF6 having common anion ( PF 6 - ). AC impedance and Raman spectroscopic measurements showed that ionic conductivity (σ) of QS-SEs increases with IL-content and partly controlled by number of free mobile ions and their mobility/polymeric chain flexibility. Differential scanning calorimetry (DSC) results showed that melting temperature (Tm), glass transition temperature (Tg) and degree of crystallinity (Xc) of QS-SEs decreases with IL-content due to the plasticization effect of added IL(BMIMPF6). Furthermore, the composition-dependent conductivity data with IL-concentration is discussed in terms of increasing amorphicity (or deceasing crystallinity) as well as ion-polymer and ion-ion interactions. Ion dynamics of QS-SEs is examined by converting the impedance data into different ionic transport formalisms like ionic mobility (μ), charge carrier density (N) using the loss tangent (tan δ) spectra and showing that amount of added IL/salt are the responsible factors for controlling overall ion transport mechanism. [ABSTRACT FROM AUTHOR]

The samples SrSnO3 (SBS0) and Sr0.98Ba0.02SnO3 (SBS2) were synthesized using sol–gel route, followed by calcination at 1073 K. Rietveld refinement analysis of XRD data shows orthorhombic phase under Pbnm space group. Lattice parameters, volume and density of the doped sample were found to be higher than undoped, due to higher ionic radii of Ba2+. Further, the Raman spectrum of samples was carried out to study the local structure. Optical properties of samples show intense absorption in UV range and transparent in visible to NIR region. The direct bandgap of samples was found to be 3.88 eV and 3.97 eV for SBS0 and SBS2, respectively, reflecting the semiconducting nature of a sample. Dielectric properties of the sample were explained in terms of interfacial and orientational polarization. Temperature-dependent conductivity analysis of the sample reflected an Arrhenius-type charge transport, with two conduction regions in SBS2 and single conduction in SBS0. In the present case, the activation energy value represents a mixed ionic and electronic conductivity of the sample, making it a promising candidate for mixed ionic and electronic conductor device application. [ABSTRACT FROM AUTHOR]

A sol-gel synthesis method was used for the synthesis of pure CoFe 2 O 4 (CFO) as well as Graphene Quantum Dots (GQDs) decorated CoFe 2 O 4 Hybrid Nanocomposite (GCHN). From X-ray diffraction (XRD) data it was analyzed that both these samples have a cubic structure with Fd-3m space group. Using Debye-Scherer's equation, the average sizes were determined to be 24.48 and 13.74 nm, respectively. FTIR spectra revealed details about vibration bands and functional groups present. Raman spectra confirmed existence of GQDs in GCHN with an I D /I G ratio of ∼0.8. The results of Field emission scanning electron microscopy (FESEM) analysis exhibited microstructural morphological details having shapes of grains to be non-uniform in shape. UV–visible data was used to calculate band gap (E g) energy by using Tauc plot method and found to be 2.52 eV and 2.99 eV respectively for CFO and GCHN. Urbach energy (E U) was found to be 1.03 and 1.19 eV for CFO and GCHN respectively. The dielectric properties of GCHN were analyzed for dependence on frequency and temperature and explained by Maxwell-Wagner-type polarization. The frequency-dependent ac conductivity (σ ac) followed Jonscher's power law and investigated dynamics of ion hopping. Impedance spectroscopy was used to further evaluate Nyquist plots with respect to temperature as well as magnetic fields to estimate grain and grain boundary contributions. This was further used to evaluate electrical characteristics such as relaxation time (τ). Activation energies (E a) calculated using relaxation times were found to be 0.48 eV for CFO while 0.22 and 0.92 eV for GCHN respectively. At room temperature, CFO and GCHN exhibited a strong magneto-dielectric coupling (MD) and showed negative magneto-dielectric properties in low-frequency regions. At room temperature (RT), magnetization values of CFO and GCHN displayed were 38.48 and 7.52 emu/g respectively. The lower magnetization value was possibly due to shielding by GQDs in GCHN. These properties enable it to be used as a potential application in microelectronic systems, spintronics, optical and optoelectronic devices, magnetic resonance imaging (MRI) and memory devices. (a) XRD pattern, (b) Frequency dependence ε at diverse temperatures (300–773 K) [Inset shows temperature dependence ε at various frequencies between 100 Hz and 1 MHz], (c) Magneto-Dielectric (MD %) coupling at diverse magnetic fields varying from 0.0 T to 1.5 T and (d) Nyquist plot of Z′ and Z″ data in between 0.0 T and 1.5 T for GCHN [ G QDs/ C oFe 2 O 4 H ybrid N anocomposite]. [Display omitted] • GQD-C oFe 2 O 4 H ybrid N anocomposite (GCHN) were synthesized using sol-gel method. • E g obtained was found to be 2.52 and 2.99 eV respectively for CoFe 2 O 4 and GCHN. • GCHN exhibited negative magneto-dielectric (MD%) and negative magneto-loss (ML%). • Impedance spectroscopy was used to further evaluate using Nyquist plots. • Magnetization value of GCHN decreased abruptly due to shielding of GQDs in GCHN. [ABSTRACT FROM AUTHOR]

NdFeO 3 (NFO) was synthesized using sol-gel citrate method and subsequent calcination at 1023 K. Utilizing Rietveld refinement analysis of the XRD pattern, it has been verified that NFO exhibits an orthorhombic crystal structure, with space group Pbnm. NFO grains were seen to be strongly agglomerated in a SEM image, despite their irregular shapes. The analysis of optical properties revealed a transmittance range of ∼20%–∼50% and an optical band gap of 2.15 eV for the NFO material. The dielectric properties of NFO were analyzed with respect to their dependence on frequency and temperature, while the ac electrical conductivity was studied in terms of its frequency variation. The dielectric dispersion behavior of NFO is explained by Maxwell Wagner-type polarization. A negative magneto-dielectric (MD) coupling of −19% and −35% was measured for ε and tan δ at 1 kHz for NFO. Magneto-impedance measurements on NFO showed positive magneto-resistance and both positive and negative magneto-capacitance, suggesting that the grain effect had a substantial role in the material's magnetic properties. These results suggest that NFO is an excellent choice for memory-based electronic devices with an appropriate band gap for optoelectronic applications having a large MD effect. Structural, dielectric properties at high temperature, magneto-dielectric effects, and Nyquist plots for NdFeO 3 nanoparticles synthesized with sol-gel citrate method. [Display omitted] • NdFeO 3 nanoparticles synthesized via sol-gel citrate method. • XRD data and Rietveld refinement identifies orthorhombic phase (Pbnm space group). • NdFeO 3 nanoparticles have a band gap of 2.15 eV and a transmittance of ∼20% to ∼50%. • Dielectric permittivity and dielectric loss show negative magneto-dielectric coupling. • NdFeO 3 show enhanced magneto-impedance characteristics using Nyquist plots. [ABSTRACT FROM AUTHOR]