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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]

The CaSn0.95Mn0.05O3 (CSMO) was produced by using the sol-gel wet chemical process. The structural composition was examined using an X-ray diffraction (XRD) pattern, and the presence of an orthorhombic structure with the space group Pbnm was confirmed by Rietveld refinement. At different temperatures between 300 K and 773 K, the dielectric permittivity (ε), tangent losses (tanδ), and electrical conductivity of CSMO has been measured as a function of frequency from 100 Hz to 1 MHz.Dielectric permittivity (ε) is found to be independent of temperature up to 400K and very low tangent loss. Jonscher's power law in the material's frequency-dependent ac conductivity shows its semiconductor nature. Optical band gap of CSMO was observed by using UV-vis.absorption spectra. The optical band gap of CSMO, which was determined using Tauc plot measurements to be 2.42 eV, suggests that the sample is a semiconductor. The Arrhenius model is employed to perform an analysis of the dc conductivity of the material concerning both frequency and temperature. As a result of its semiconductivity, stable dielectric constant, and low tangent loss, CSMO is a suitable material for thermally stable capacitors, semiconductor devices, UV filter and UV detectors. [ABSTRACT FROM AUTHOR]

The CaSn0.95Mn0.05O3 (CSMO) was produced by using the sol-gel wet chemical process. The structural composition was examined using an X-ray diffraction (XRD) pattern, and the presence of an orthorhombic structure with the space group Pbnm was confirmed by Rietveld refinement. At different temperatures between 300 K and 773 K, the dielectric permittivity (ε), tangent losses (tanδ), and electrical conductivity of CSMO has been measured as a function of frequency from 100 Hz to 1 MHz.Dielectric permittivity (ε) is found to be independent of temperature up to 400K and very low tangent loss. Jonscher's power law in the material's frequency-dependent ac conductivity shows its semiconductor nature. Optical band gap of CSMO was observed by using UV-vis.absorption spectra. The optical band gap of CSMO, which was determined using Tauc plot measurements to be 2.42 eV, suggests that the sample is a semiconductor. The Arrhenius model is employed to perform an analysis of the dc conductivity of the material concerning both frequency and temperature. As a result of its semiconductivity, stable dielectric constant, and low tangent loss, CSMO is a suitable material for thermally stable capacitors, semiconductor devices, UV filter and UV detectors. [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]

Significant efforts have been devoted to the synthesis of conjugated molecules due to their interesting properties for organic electronic applications, it is surprising that very few studies have been reported on the development of small molecules for hole transport material (HTM) in organic solar cells through direct C−H arylation. In this work, we have studied the reaction conditions used for the facile synthesis of a series of π conjugated small molecules through direct C−H arylation. The reaction condition was optimized by using different solvents, bases and ligands to achieve the maximum possible yield. Ten phenyl(s)‐flanked conjugated small molecules were prepared using the optimized reaction condition and were characterized. Density functional theory was studied on these molecules to understand the structure‐property relationship and predicting the reliable geometry, electronic structure and properties of conjugated systems. Electrical and optical properties were measured by cyclic voltammetry and UV‐vis absorption spectroscopy. Finally, the organic solar cells were fabricated by solution‐processable deposition of these HTM with device geometry of ITO/HTM/PCDTBT:PC70BM/Al and achieved a power conversion efficiency of 2.40 % under ambient conditions. This method has the advantages of using different aromaticity of heterocyclic rings combined with conjugation length and electronegativity of heteroatom(s) to allow fine‐tuning of HOMO level and band gap engineering. [ABSTRACT FROM AUTHOR]

0.8BiFeO 3 -0.2CaTiO 3 (0.8BFO-0.2CTO) was synthesized by the sol-gel route. Structural characterization was performed by X-ray diffraction which confirms the rhombohedral structure. FESEM analysis reveals the irregular grains that are inhomogenous and slightly dense. Temperature-dependent dielectric permittivity shows a dielectric anomaly near the magnetic phase transition temperature (T N) of BiFeO 3 as well as relaxor-type ferroelectric properties. The PE loop confirms the presence of ferroelectricity in the sample. Frequency-dependent ac conductivity exhibits low frequency dispersion and was well explained by Jonscher power law. The obtained fitting parameters A (pre-exponential factor that indicates polarizability) and n (dimensionless frequency exponent) show maxima and minima at the transition temperature. The electrical properties were further analysed by impedance and modulus spectroscopy. According to these analysis, the relaxation time was distributed and does not follow the Debye type behaviour. Nyquist plots had been used to estimate grain and grain boundary contributions. A typical negative temperature coefficient of resistance (NTCR) behaviour was apparent due to the decrement in bulk and grain boundary resistances as the temperature increases. The temperature-dependent relaxation time revealed Arrhenius's behaviour. 0.8BFO-0.2CTO exhibits absorption and shows a transmittance of 40–44% in the visible region of spectra. The obtained value of E g was ∼2.26 eV, which implies the application in ultrafast optoelectronic devices. The good ability of absorption in visible region, high transmittance, the increase of extinction coefficient with wavelength, and low band gap makes 0.8BFO-0.2CTO an extraordinary material for optical devices application. The sample also shows a decrease in magneto-capacitance and increase in magneto-impedance which reflects the presence of strong magneto dielectric coupling in 0.8BFO-0.2CTO at room temperature. • Sol-gel synthesis is used to synthesize 0.8BFO-0.2CTO composites. • Composite 0.8BFO-0.2CTO exhibits relaxor-type ferroelectric behavior. • AC-conductivity shows NTCR behavior and follows Jonscher's power law. • Non-Debye type relaxation phenomenon is observed with a decrement in relaxation. • At room temperature, magneto-dielectric coupling is investigated. [ABSTRACT FROM AUTHOR]