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Bimetallic nanostructures can exhibit significant broadening of Mie resonances compared to monometallic nanoparticles. Here, we study these materials using Electron Energy Loss Spectroscopy at a single particle level. This technique is immensely effective to probe direct structure-property correlation of nanoparticles. We are thus able to confirm the broadening of Mie resonances at a single particle level. This effect is analyzed in the context of emergence of a new dielectric constant that originates from metallic interfaces. We employ Coronado-Schatz corrections to the usual dielectric constants of the constituent metals to quantitatively simulate these materials. The resultant materials thus exhibit optical cross-sections that are 38.5 % and 4.2 % of the gold and silver nanoparticle optical cross-section at 2.5 eV and 3.45 eV, respectively. A strong agreement between theory and experiment is observed. We also confirmed the effectiveness of our approach for nanoparticles with different morphologies as well as different compositional ratios. Our study suggests an effective strategy to regulate the dielectric properties of bimetallic nanostructures through interface engineering.

This paper reports the dielectric behaviour and electrical conduction properties of Y6-xBa4Ybx(SiO4)6O2 (YBaSiO: xYb) compounds. The Scanning Electron Microscopy (SEM) was utilized to obtain the surface microstructure of the compound. The micrographs showed both the circular and elongated shape of grains and their random distribution. The Fourier Transform Infrared Spectroscopy (FTIR) was used to confirm the presence of bond formations in the compounds. From the spectra, it was observed that the peaks at 690 cm−1 and a band from 850 cm−1 to 998 cm−1 are due to the stretching frequency of Y-O molecules and Si-O molecules, respectively. The peak centred at 1464 cm−1 is of vibration modes of Ba2+ions. These peaks confirmed the formation of oxy-apatite compounds. Both the dielectric permittivity and dielectric loss, decreases with increasing values of frequency due to reduction in the polarization effects on the higher side of frequency. This is because the dipole orientation lags with the rapidly reversing alternating current (ac) field. The value of dielectric loss was found to range between, 0 – 3.5 in frequency ∼ 100 Hz and 0 – 0.5 in frequency ∼ 100,000 Hz, up to temperature 500 °C. The impedance value decreases and hence a. c. conductivity increases, at higher frequencies. The increment in ac values followed the universal power law. The Nyquist plot showed that the area under the curves reduces and hence indicates negative temperature coefficient of resistance i.e., NTCR behaviour of compounds. The obtained results suggest the utilization of compound in electrical devices as power loss component, solid oxide fuel cells, and capacitors etc.

Barium Bismuth Ferrite nanoparticles having the general formula Ba1-xBixFeO3 were successfully made by the sol-gel system, using nitrates as the fundamental material. Tartaric acid and polyvinyl alcohol were used as chelating agents. The synthesized nanoparticle powder was sintered at 650 ̊C and 750 ̊C for 3 h. Filtering with dilute nitric acid and distilled water is used to remove the impurities. The structural, optical, and dielectric properties were determined at room temperature. Using X-ray diffraction (XRD) analysis, structure, lattice parameter, microstrain, and dislocation density were calculated. Using the Scherrer equation, the peak's crystalline size was ascertained. In FTIR, the vibrational modes of the octahedral and tetrahedral metal complexes in the sample have been studied using the wavenumber in this range. The synthesized nanocomposite contains morphological features, such as interconnecting agglomerates with spherical, irregular, or non-uniform elongated shapes, as demonstrated by SEM images. The activation energy for relaxation and activation energy for conduction was measured from the Cole-Cole plot and the AC conductivity versus frequency plot respectively. The determined activation energies from the two investigations were relatively close to one another. The Barium Bismuth Ferrite nanoparticles samples at room temperature indicate that the samples have implicit candidates for information storage devices for spintronic devices. In the high frequency range, all samples depending upon the temperature demonstrate excellent dielectric behaviour and small dielectric loss, and with stable dielectric constant, these samples make their prospective for the practical application in spintronic devices the main goal of this work.

Radix Glycyrrhizae, the dried roots of the Glycyrrhiza glabra plant, is a popular Chinese herbal medicine known for its various health benefits. It is particularly effective in relieving respiratory problems like coughs, sore throats, bronchitis, and asthma. However, there is limited research on the electrical properties of Radix Glycyrrhizae, likely due to its complex composition of phytochemical and antioxidant activities. This research aims to investigate the potential of these active biological compounds and understand their electrochemical properties. In this study, High-Performance Liquid Chromatography (HPLC) analysis revealed that Radix Glycyrrhizae decoction contains significant amounts of flavonoids and saponins, compounds known for their health benefits and therapeutic effects. Further analysis using Fourier Transform Infrared Spectroscopy (FTIR) identified several functional groups, including phenols, alcohols, alkynes, alkenes, ethers, and glycosides, which contribute to the plant's medicinal potential and affect the impedance and dielectric properties of the extract. The antioxidant activity of Radix Glycyrrhizae decoction was also evaluated using DPPH assays, showing similar radical scavenging activity to gallic acid. Dielectric and impedance measurement of Radix Glycyrrhizae extract were performed using an Agilent vector network analyzer and a Hioki impedance analyzer. The dielectric constant measured was consistent across both analyzers. However, the loss factor showed different trends: the vector network analyzer indicated a decrease in the loss factor with increasing frequency in the range of 5 MHz–20 GHz, while the impedance analyzer showed the opposite trend in the frequency range of 4 Hz–5 MHz.

The synthesis and characterization of PVA-chitosan-NiO, PVA-chitosan-TiO2, and PVA-chitosan-TiO2@NiO films have opened avenues for tailoring materials with specific electrical, dielectric, and optical properties. The synergistic effects arising from the combination of polymers and metal oxides offer a platform for further optimization and application-specific tuning. The synthesis process successfully incorporated NiO and TiO2 nanoparticles into the PVA-chitosan matrix, creating three distinct films: PVA-chitosan-NiO, PVA-chitosan-TiO2, and PVA-chitosan-TiO2@NiO. Structural analyses, including X-ray diffraction (XRD) and scanning electron microscopy (SEM), revealed well-defined nanostructures with crystalline metal oxide dispersions. Dielectric characterization demonstrated frequency-dependent behavior, elucidating the influence of metal oxides on dielectric constants and loss tangents. Cole–Cole plots provide insights into relaxation processes and can guide applications in capacitors and energy storage devices. Conductivity measurements highlight the enhanced electrical performance of NiO and TiO2. This study provides a foundation for future research on the development of advanced functional materials for a wide range of technological applications. The insights gained from this work contribute to the growing body of knowledge on polymer-metal oxide composites and pave the way for innovations in electronic, optoelectronic, and energy-related technologies.

The advancement of future electronic devices necessitates dielectric materials with enhanced compositional complexity and improved capabilities. We here demonstrate a gas-phase alloying approach that yields ultrathin and crystalline dielectrics with attractive properties for the integration into electronics. A surface-selective deposition process was shown to produce sulfur (S) and selenium (Se) alloys with large-scale uniformity. Through combination of experimental diffraction analysis and materials modeling, we establish the crystallinity of the alloy with a modified lattice structure compared to the host materials. The resulting lattice arrangement endows the alloy dielectric with high ionic mobility as validated by electrochemical impedance spectroscopy. Leveraging this innovative feature, we fabricate memristive devices exhibiting promising performance characteristics. Our findings demonstrate the feasibility of utilizing gas-phase alloying to engineer dielectrics with superior properties and functionality for future device integration.

Here we report the synthesis of Sm-doped Na0.5Bi4.5Ti4O15 (Na0.5Sm0.5Bi4Ti4O15) lead-free ceramics via a conventional solid-state technique. Investigations of Na0.5Bi4.5Ti4O15 (NBT) and Na0.5Sm0.5Bi4.5Ti4O15 (NSBT) ceramics were demonstrated in detail to understand the composition-based structure-property of Aurivillius compounds and related functional material. Dielectric properties for frequency and temperature in a wide range were analyzed. The conduction activation energy values of NSBT ceramics are obtained to be 1.40 eV, whereas, the NBT ceramics get the value to be 1.31 eV. At higher temperatures, the conduction activation energy value of NSBT ceramics is 1.32 eV for both frequencies of 100 Hz and 1 kHz, whereas, for NBT compounds, the calculated value is 1.27 eV for both frequencies. The simulation performed on the impedance data for capacitive and resistance elements shows well-fitting curves which indicates a single relaxation behavior in the material. Similarly, the AC-conductivity data were analyzed which gives different conduction processes and relaxation activation energies in the NSBT ceramics.

The electrical properties of bismuth magnesium tantalate pyrochlore, Bi3.30Mg1.88Ta2.82O13.88 (BMT) were investigated by both inductor-capacitor-resistor (LCR) and impedance spectroscopy techniques covering a broad temperature range of 10–1073 K and a frequency range of 5 Hz - 1 MHz. At below ∼180 K, BMT pyrochlore exhibited interesting relaxor behaviour that showed high dispersion characteristics in its frequency-temperature dependent dielectric constants, ε′ and dielectric losses, tan δ, respectively. The maximum ε′max of ∼77 was obtained at the temperature maximum, Tm of 154 K. The frequency-independent ε′ data above 154 K at a fixed frequency of 1 MHz can be well fitted with the Curie-Weiss law and the relaxation features of Bi3.30Mg1.88Ta2.82O13.88 obeyed the Vogel-Fulcher equation. The dielectric properties of Bi3.30Mg1.88Ta2.82O13.88 relaxor in the low temperature range of 20–320 K could be satisfactorily modeled with different equivalent circuits. In this perspective, a master circuit consisting of a parallel R-C-CPE element in series with a capacitor was required to accurately fit the low temperature data.

Copper Oxide (CuO) nanoparticles were synthesized by the solution combustion method. The crystallite size of the particles was determined using X-ray diffraction (XRD). The elastic properties of prepared nanomaterial were also studied using ELATE software. The dielectric properties of CuO nanoparticles were carried out at room (30 °C) and elevated temperatures (50–200 °C). The variation of the alternating current (ac) conductivity (σdc), dielectric constant (k), dielectric loss (tanδ), impedance (Z) and electric modulus (M) were studied as a function of frequency and temperature. The results showed that the dielectric properties and ac conductivity of the prepared nanoparticles were dependent on frequency and temperature. The prepared nanoparticles can be used for energy storage applications.

The present study made an attempt to develop a conductive hemp fiber (HF) through an electroless Ni-P composite coating with reduced graphene oxide (rGO) as reinforcement. Four different Ni-P/rGO coated fibers were prepared with the variations in the coating time (20/40 min) and weight percentages of rGO (5/10 %). The coated fibers were characterized using various tools like: Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and field-emission scanning electron microscopy (FESEM), to identify the functional groups, phase structure, and morphological changes, induced by the rGO reinforcement. The coating duration and weight percentage of rGO had influenced the dielectric properties and electrical conductivity. In comparison, the coating duration of 40 min with 10 % addition of rGO has enhanced the electrical conductivity to 13.75 % and 37.5 % respectively. Furthermore, the mechanism behind the improvement in the conductivity is detailed in this study.

Dielectric ceramics are promising in large-scale commercial millimeter-wave communication technology, such as 5G and the upcoming 6G, thanks to their excellent frequency selection characteristics and environmental stability. In this work, various contents of SbO bonds were introduced into the MgTa2O6 lattice using the solid-phase reaction method to investigate the effects on the lattice and microwave dielectric properties. XRD confirms that Sb ions successfully occupy Ta sites in the lattice and cause lattice shrinkage and crystallinity deterioration, which leads to a slight decrease in the quality factor. Furthermore, DFT calculations reveal that the doping leads to electron-biased aggregation toward O atoms, causing higher SbO ionicity, but also attenuates the degree of ionization of Ta and Mg ions, which makes the dielectric constant of the doped samples vary non-monotonically with gradient doping. Satisfactorily, Sb doping substantially enhanced the thermal stability of the ceramics, with TCF values reduced from 36 × 10−6 °C-1 to 15 × 10−6 °C-1.

The standard solid-state reaction method is used to synthesize Aluminium (Al) substituted lithium-nickel-manganese ferrites. The synthesized samples were sintered at a temperature of 1200⁰C for 5h. The confirmation of single-phase cubic spinel structure is revealed by Reitveld refinement analysis. The average grain size is determined to be within the range of 1.72 to 0.91 μm based on the analysis of surface morphology. The densities showed a slight declination with Al contents because the Al3+ ion has less molecular weight than the Fe3+ ion and porosity increased gradually. The real part of initial permeability (μiʹ) is gradually decreased with Al substitution. The lowest value of magnetic loss (tanδM) and the highest value of μiʹ is obtained for the mother material (μiʹ=68.5). The maximum value of relative quality factor (RQF) is found for x=0.20 sample and is approximately 1600. The sample of x=0.00 comprises the large value of saturation magnetization (=89.7 emu/g). Through the analysis of frequency-dependent dielectric constants and AC conductivity, it can be seen that the synthesized ferrites exhibit a high level of resistivity. The dielectric characteristics of the Al-substituted samples are improved, and the maximum dielectric constant (ɛ') of 3200 is observed for the x=0.40 sample at 102Hz. The Nyquist plot indicates that grain boundary contribution is significant to the conductivity mechanism of the compositions and that the materials exhibit non-Debye-type relaxation of conductivity. The studied samples showed ferroelectric properties with lossy behavior.

The sol-gel process was used to prepare zinc doped magnesium ferrite (Mg1-xZnxFe2O4) nanopowders obtained from the nitrates of magnesium, zinc and ferrous is precursor materials, maintain the pH value which were then studied for sensing purposes. The crystallite size and phase of the ferrite samples studied by X-ray diffraction (XRD) revealed a pure spinel phase (Mg1-xZnxFe2O4) with a cubic spinel structure and higher crystallite size and etc. The functional groups with possible stretching analysis were taken from Fourier transform infrared spectroscopy (FTIR). The surface features and morphology and the purity of the samples were analysed through a Scanning electron microscope (SEM) and energy dispersive X-ray (EDAX) spectrum respectively. Through the vibrating sample magnetometer (VSM), the magnetic behaviour was studied from relevant parameters such as saturation magnetization (Ms), coercivity (Hc) and retentivity (Mr). The larger Ms in 0.8 has ferromagnetic nature were observed. The dielectric constants (ε’& ε’’), dielectric loss (tan δ) with AC conductivity (σAC) determined through the LCR metre, and electrochemical behaviour of the samples were found through cyclic voltametery. The possible polarizations at lower and higher frequencies are studied The obtained data are extensively examined and understood.

The mineral composition, crystallinity, and dielectric properties of salts can provide valuable insights into the quality and suitability of different types of salt for various applications. In this study, comprehensive analysis of the X-Ray Diffraction (XRD), X-ray fluorescence (XRF) and dielectric analysis of the Ba'kelalan salt, Himalaya salt and Bamboo salt have been investigated. The mineral composition of these salts, encompassing vital elements such as iodine and other trace minerals, significantly influences the salt's nutritional profile and overall excellence. Nonetheless, gauging the dispersion and density of these minerals poses difficulties due to conventional techniques that can be arduous, damaging, and expensive. Sample preparation is carried out before conducting X-ray diffraction (XRD), X-ray fluorescence (XRF), and dielectric analysis. XRD measurements are performed using the Bruker D2 Phaser to identify crystalline material phases. XRD operates on the principle of constructive X-ray interference within crystalline samples. For elemental analysis across a broad spectrum of materials, XRF is employed. Elemental peaks are scanned, starting from the lowest to the highest angle of incidence. The X-ray intensity at characteristic peaks is compared to the standard series. Dielectric spectroscopy analysis examines the dielectric behaviour of Ba'kelalan salt, Himalaya salt, and Bamboo salt. The setup involves a vector network analyser (VNA) paired with an open-ended coaxial probe, utilizing the microwave method. This approach ensures rapid, efficient, and non-destructive measurements of dielectric constants (ε′) and loss factors (ε”). The dielectric permittivity spectra are acquired within the frequency range of 4 GHz–20 GHz. ε′ of these salts increase with frequency. Meanwhile, ε” seem varies insignificantly over frequency. Mineral contents and crystallinity are the crucial factors lead to these responses. Based on the study, the quality and suitability of the selected salts for specific applications can be determined by considering their mineral composition, crystallinity, and dielectric properties in the context of the intended use. This gives an insight for some applications that may benefit from certain minerals or crystalline structures, others may require specific dielectric properties for effective use. Therefore, understanding these properties allows for decision-making in choosing the right type of salt for a given purpose, whether it's for foods, medical, industrial, healthcare, and technological applications.

An organic salt 4-N,N-dimethylamino-4′-N’-phenyl-stilbazolium hexafluorophospate (DAPSH) was synthesized by metathesization process using acetonitrile solvent and DAPSH was crystallized by slow evaporation method. Single crystal X-ray diffraction (SXRD) analysis of DAPSH crystal revealed that the crystal possesses monoclinic crystal system with the non-centrosymmetric space group Cc. The existence of various functional groups present in the titular material is affirmed using FTIR analysis. UV–vis-NIR spectral analysis revealed the optical absorption of DAPSH crystal and the band gap as 3.1 eV. The elemental percentage composition was verified by CHN and EDAX analysis. Vickers Microhardness testing was used to assess the mechanical stability of the produced crystal. The DAPSH crystal is stable up to 250 °C, according to thermal analysis. The Kurtz and Perry NLO test confirms DAPSH's second harmonic generation (SHG) ability. The dielectric measurement was conducted in the frequency range from 50 Hz to 5 MHz for different temperatures (313, 323, 373, 423 and 473 K). The crystal exhibited low dielectric loss in the high frequency region and AC conductivity was calculated from the dielectric data. The anticancer and toxicity properties of the produced DAPSH crystal were investigated and it was confirmed to be an effective substance against cancer cells.

The polycrystalline Li0.15Ni0.6-xZnxCu0.1Fe2.15O4 ferrites are fabricated by the method of conventional solid-state reaction technique. The X-ray diffraction (XRD) confirms that the structure of the composition is a single-phase cubic spinel structure for all samples. The particle size of the compositions is varied from 36 to 52 nm. The lattice parameter and densities are found to increase with enhancing Zn content, as the ionic radius and atomic weight of Zn are greater than Ni. The porosity exhibits a decreasing trend. The average grain size determined using Field Emission Scanning Microscopy (FESEM) increases until x = 0.40, then declines. The Energy-Dispersive Spectroscopy (EDS) examination revealed that the percentage of obtained elements is well matched with the stoichiometric elements. The addition of Zn content acts as an accelerator for enhancing the value of the real part of initial permeability and the highest value is obtained (μiʹ = 276) for the x = 0.40 sample, as well as the highest relative quality factor (RQF) of around 3000. The loss factor for the Zn substituted composition is nine times lower than for the parent composition. The optimum saturation magnetization of around 77.49 emu/g is found for the x = 0.40 sample. The maximum dielectric constant (εʹ = 2.85 × 103) is found for x = 0.10 samples at 10 kHz. Further, from impedance studies, the non-Debye type dielectric relaxation is seen for the Zn-substituted samples. The observed region of the imaginary electric modulus peak signifies the transition of charge carrier mobility from a larger range to a short-range distance. The phenomenon of ac conductivity is attributed to the process of the small polaron hopping mechanism.

The effects of Na+ substitution by Y3+ on the structural, microstructural, dielectric and electrical properties of Ba2Na(1-3x)YxNb5O15 compositions with (x = 0, 0.02 and 0.04) have been studied in detail. The solid solutions of different compositions were prepared by the solid state reaction route method and characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Complex Impedance Spectroscopy (CIS) techniques. The XRD study confirmed that all prepared compositions have a single-phase orthorhombic tungsten bronze structure with space group Cmm2 at room temperature. The microstructural studies revealed a grain shape and size change in response to increasing Y3+ concentration. The dielectric properties of the obtained compositions are evaluated over a temperature range of 40–600 °C. The dielectric properties were improved for the Y2O3-substituted Ba2NaNb5O15 compound compared to the undoped Ba2NaNb5O15 compound. The non-Debye type relaxation mechanism is confirmed by the -Z″ versus Z′ traces. The grain contribution was studied using an equivalent electrical circuit with a Resistor R, a Capacitor C, and a Constant-Phase Element CPE in parallel, in the absence of the grain boundary response and the electrode effect in the frequency range 10 Hz-1MHz. The experimental AC conductivity data were evaluated by using Jonscher's power law. The activation energies obtained from the relaxation and conduction processes, present two different regions as a function of temperature related to the two electrical processes for the prepared ceramics.

This work employed pulsed laser ablation to produce cellulose acetate butyrate-gold (CAB-Au) nanocomposite films and the evaluation of their structural and thermal characteristics using Raman, X-ray diffraction (XRD), thermogravimetric analysis (TGA), and Differential Scanning Calorimetry (DSC). In the frequency range 0.1–10 MHz, nanocomposite films' dielectric constant, loss, and electric modulus behavior were investigated as a function of temperature. The refractive index, finesse coefficient, Brewster coefficient, critical angles, dielectric function, and color properties of nanocomposite films were examined in the wavelength range 190–800 nm. X-ray diffraction shows a strong Au diffraction signal in all samples, confirming Au NPs. The SEM micrograph shows Au embedded in CAB. The CAB-Au nanocomposites had higher thermal stabilities (Tm) than pure CAB, and the DSC thermograms showed a fluctuating glass transition temperature due to the dynamics of organic-inorganic interactions in the nanocomposite films. Dielectric dispersion is caused by hidden dipolar polarization. The CAB (5 min) sample had the highest ac conductivity as a function of frequency at various temperatures as the Au content in the Au/CAB composite rose. The simplest quantum mechanical tunneling (QMT) model also best explains the ac conduction property. We found a relationship between the nanocomposites' refractive index and the amount (extent of incorporation) of Au in the materials, with laser irradiation time determining the various color constants. Tauc plots reveal a permitted transition with an optical energy gap of 5.1eV for the polymer film and 4.75eV after 10 and 20 min of laser irradiation.

In new research growth long after glow material is a potential candidate due to its physical properties, chemical stability and wide application in modern solid-state lightning (LED), display devices, dosimetry and sensors. A cerium doped strontium aluminate phosphor (SrAl2O4:Ce3+) was synthesized by conventional solid-state reaction method. The crystal structure and morphology of phosphors, while doping rare earth metal and lithium metal ion was investigated by using X-ray diffraction, Raman spectroscopy and field emission scanning electron microscopy. Fourier transformed infrared spectrum results of the synthesized phosphor composition conforms the characteristic vibration bands of synthesized phosphor. Surface composition analysis of the prepared samples was examined using X-ray photoelectron spectroscopy. Photoluminescence emission band observed at ∼420 nm, ∼490 nm and ∼610 nm region under the excitation wavelength of 256 nm. Wight light emission was confirmed using the Commission Internationale de L'Eclairage (CIE) chromatic coordinate graph. The correlated colour temperature (CCT) value of 0.5% Ce3+ doped SAO of phosphors was calculated is in the range of 1543 K, which is indicated the synthesized phosphors performance as warm white light source. The obtained phosphor has a high dielectric constant and low loss tangent which is useful to optoelectronic devices.

This paper discusses the synthesis, dielectric properties, and applications of ZnFe2O4 for the thermistor. A high-temperature solid-state reaction method is used to create the polycrystalline ZnFe2O4 sample. The X-ray diffraction study identified the single spinel Cubic phase formation at room temperature without any impurities. The broadening of the XRD peaks determined structural parameters including crystallite size, microstrain, dislocation density, and percentage crystallinity which confirms the lower number of lattice defects in the ferrite. The dielectric properties of the sample are investigated as a function of temperature over selected frequencies. The high dielectric constant and low dielectric loss of the material suggest that it can be used in advanced energy storage systems. The minimal activation energies in the high-temperature region determined from the slope of the linear fit of the temperature-dependent curve indicate the enhancement of electrical conductivity. Looking into the strong dependence of resistivity on temperature, the thermistor parameters are evaluated using the resistance at different temperatures, which suggests its possible application for a thermistor as well as a temperature sensor. The calculation of different thermistor parameters such as thermistor constant, sensitivity factor, and activation energy confirms a negative temperature coefficient of resistance behavior of the ferrites at different temperatures and frequencies.

In recent years, more and more research was conducted to explore smaller and smaller systems that become similar to an actual micro/nano-robot. The major roadblock regarding their real world implementation is the highly restricted available volume. In this paper, we introduce folding – hence an origami technology using Al2O3 as building material, which is compatible with current Si technology. High quality 50 nm thin Al2O3 film is grown by atomic layer desposition, patterned, thinned and then released from the Si subtrate using SF6 plasma etching. The realized free standing Al2O3 structure would fold itself at predefined regions due to the stress in the as deposited films. We believe such technology could offer a new possibility to tackle the problem of efficiently using the volume. Al2O3 could act as both the structural origami material and the functional gate dielectric material for electronics. This approach enables the feasibility of patterning devices and circuits on every Al2O3 facet of a 3D object, while the inside volume of this object is still available for 3D bulk device components. We demonstrate the optimized etching process as well as an emperical improvement of the folding hinges and of the overall structural stability.

The hydrothermal approach was adopted for the fabrication of zinc oxide (ZnO) nanofibers. The effect of hydrothermal reaction time (1–20 h) was studied on the basis of dielectric, structural, morphological and optical properties. The techniques, i.e., X-ray diffraction (XRD), Fourier transform infrared microscopy (FTIR) and energy dispersive spectrum (EDS) were employed for the characterization of ZnO nanofibers (NFs) formation. In XRD studies, reflection planes (1 0 0), (0 0 2), (1 0 1), (1 0 2), (1 1 0) and (1 0 3) are well matched with wurtzite ZnO hexagonal structure. The presence of ZnO NFs at 20 h of reaction time can be attributed that intensity along (0 0 2) plane becomes stronger or preferential growth on 1D. Structural defects were calculated by employing the dislocation density. The grain size of ZnO NFs was in 18.4–29.7 nm range. The absorption peak at 605 cm−1 (at higher reaction temperature) confirms the formation of 1D nanostructure. SEM analysis reveals the ZnO NFs formation at higher hydrothermal reaction time and EDS confirms the purity of ZnO samples (77.67% of Zn and 22.33% of O). The optical properties found to be also affected as a function of hydrothermal reaction time. Findings revealed that the ZnO can be fabricated by hydrothermal treatment to enhance the dielectric, structural and optical properties for photocatalytic application.

Nano-composites ceramic of (Al2O3/BaTiO3) were successfully fabricated by Sol. Gel. technique with a weight ratio of Al2O3: BaTiO3, 1:100 wt%, respectively. X-Ray diffraction (XRD), Infrared (FT-IR), scanning electron microscopy (SEM) and Raman spectroscopy have been used to characterize the fabricated samples. Experimental data revealed that adding of Al2O3 changed both the structure and particle size of BaTiO3 from tetragonal with 7–9 μm to orthorhombic with 400–600 nm for Al2O3/BaTiO3. Moreover, SEM shows uniform grains distribution with nano-sized particles. Raman spectra shows a peak at 900 nm for BaTiO3 and split for Al2O3/BaTiO3. The FT-IR recorded several peaks related to Al2O3/BaTiO3 at low wavenumber

Chemical bath deposition, being an application oriented electroless technique, is used for the deposition of calcium doped barium titanate (Ba1-xCaxTiO3) thin films using glass substrate. Ca concentration is varied as x = 0.0, 0.02, 0.04, 0.06, 0.08, 0.10 and 0.12. As-deposited thin films show amorphous behavior, whereas, annealed thin films show crystalline nature. X-ray diffraction (XRD) analysis of annealed thin films shows a pure tetragonal phase of Perovskite barium calcium titanate thin films up to x = 0.08 dopant concentration, while XRD peak corresponding to CaO is observed at x = 0.10 and 0.12. Maximum optical transmission of 65% is observed under undoped and as-deposited conditions. Annealed thin films show 83% transmission under undoped condition. While decrease in transmission is observed with the increase of dopant concentration due to the presence of sub bands. High value of dielectric constant (i.e. ∼3800 at log f = 1.3) and low value of tangent loss (i.e.∼0.15 at log f = 1.3) is observed for x = 0.08 dopant concentration. Cole–Cole plots reveal the presence of two electrically active grains and grain boundary regions. Maximum value of spontaneous polarization Pmax (18.46 μC/cm2) is observed for x = 0.08 dopant concentration. Mixed para-ferromagnetic response is observed under undoped condition. S-shaped magnetic response is observed for x = 0.02–0.04 whereas, ferromagnetic curves are observed for x = 0.06–0.12. It is important to mention here that tetragonal Perovskite calcium doped barium titanate thin films with U-shaped dielectric constant and good ferroelectric properties are hard to find in literature.

Nickel and Cobalt ion containing silica based nanoglasses confined within mesoporous SBA-15 and mesoporous alumina templates were synthesized by sol-gel process. These nanocomposites were investigated to understand their microstructure, magnetization dynamics and magnetic memory effects near transition temperatures using state-of-the-art characterization techniques including XRD, TEM and SQUID. The temperature and frequency dependent dielectric properties and Nyquist plot were also investigated. The effect of transition ions and template on memory effect and relaxation dynamics of spin glass phase were explained with Scaling and Vogel-Fulcher laws. The mechanism accountable for the observed characteristics of these nanoconfined amorphous systems are explained systematically. The polarization mechanisms as a function of temperature and frequency were also investigated comprehensively. This study provides an advanced understanding of magnetization dynamics and dielectric property in nanoglass system which will be of fundamental and technological interest that will help to tune and fabricate advanced functional nano materials.

Use of microwave (MW) energy as an alternate to high temperature treatment during material synthesis is gaining much attention as it offers the advantages of being faster and economical than other heating methods. A comprehensive study of structure, magnetization, and polarization behaviour of Cobalt (Co) doped Fe3O4 thin films, prepared by means of microwave assisted sol–gel method is performed. Co doped (0-10 wt%) sols are prepared after irradiating them at MW power of 1000 W. Phase analysis is confirmed using XRD where Fe3O4 phase persisted with Co concentrations of 0-6 wt%. Higher concentration results in the appearance of cobalt oxide phase. Magnetic and transport properties are strongly affected by the presence of Co ions. Co doped Fe3O4 films show anisotropic behaviour with high saturation magnetization obtained for 6 wt% Co doped Fe3O4 thin films, i.e. ∼ 125 emu/g. Verwey transition is observed for thin films with low dopant concentration while no sharp transition in magnetization behaviour is observed for higher dopant concentration. High frequency anomaly in dielectric analysis is observed at high frequencies for Co doped Fe3O4 thin films. Negative values of magneto-dielectric coefficient show coupling of magnetic and dielectric behaviour at room temperature.

The complex chemical and structural heterogeneity of relaxor ferroelectrics has made the origins of the giant piezoresponse extremely difficult to understand. Here, we successfully grew Ho-doped Pb(Mg1/3Nb2/3)O3–PbTiO3 (Ho-PMNT) single crystals with even higher d33, S33 and dielectric constant ε33/ε0 values of 3900 pC N−1, 0.34% and 15,000. We employed the in situ neutron diffraction to identify that the giant piezoelectric response of the Ho-PMNT originates from the composition near the tricritical triple point of a cubic paraelectric phase (C), ferroelectric monoclinic (M), and tetragonal (T) phases. It leads to a nearly polarization isotropy and thus facilitates polarization rotation between different ferroelectric states. The results of the neutron pair distribution function combined with aberration-corrected scanning transmission electron microscopy qualitatively analyze the angstrom-nanoscaled heterogeneities and their connection to local polarization. The Pb2+ displacement direction of is connected to the A site ordered polarization. There were also observed the different separation distances between the B-site atoms and the neighboring O atoms. It identifies the giant piezoelectric properties arise that the Ho-dopant immensely disrupt long-range polarization and enhance the local structural heterogeneity in the tricritical triple point.

In this work, multi-layer PECVD SiNx/SiNx and SiNx/SiOy passivations are developed featuring very high soft breakdown strength and tunable stress properties, which would allow for stress engineering and wafer bow minimization. AlGaN/GaN-on-Si wafers (150 mm) with very low initial bow (

A nanoscale stretching-induced one-dimensional (1D) nanofiller orientation in a three-dimensional (3D) film (the films form cell walls of foamed materials) is beneficial for improving the dielectric and electromagnetic interference (EMI) shielding properties of composite systems. However, nanoscale stretching may cause nanofiller separation, negatively impacting their properties. In this study, a two-dimensional (2D) nanofiller was introduced into a carbon nanofibre/poly(vinylidene fluoride) (CNF/PVDF) nanocomposite system to improve the nanoscale confined-space stretching effect. As a result, the degree of in-film orientation of the CNFs was significantly improved. Based on this effect, boron nitride was used as a 2D dielectric nanofiller to improve the degree of in-plane orientation of CNFs and to prepare 3D nanocomposite films with improved dielectric properties (improved by 54.3 %). Furthermore, 2D conductive nanofiller graphene nanoplatelets (GNPs) were employed to improve the degree of in-film orientation of CNFs for the preparation of CNF/GNP/PVDF nanocomposite foams with improved electrical conductivity and EMI shielding performance (increased by 89.4 %, from 18.8 to 35.6 dB·g−1·cm3 at 10 GHz). A Monte Carlo simulation was used to verify that the 2D nanofiller improved the 1D nanofiller orientation in the 3D nanocomposite film. This study provides a guide for the design of high-performance foamed nanocomposite materials.

In the present study, a solid-state reaction technique is used to formulate and synthesize the (Ca0.5W0.5)(Pb0.5Ni0.5)O3, [CWPN] relaxor perovskite composite. Its structural, morphological, and electrical characteristics have all been revealed so that they may be studied for potential use in electronics and sensors. X-ray diffraction analyses have confirmed the structure to be combination of primary tetragonal along with secondary rhombohedral and orthorhombic phase. Throughout a wide temperature and frequency range (25° – 500° C and 1 kHz–1 MHz), the impedance spectroscopy, dielectric, and a.c. conductivity have all been analyzed. The sample's dielectric spectroscopy confirmed its relaxor properties. On a Nyquist plot, the sample's grain contribution is represented by a single semicircular arc. A replica of a similar circuit was constructed so that its electrical characteristics could be studied. Both the activation energy and the mobility of the charge carriers have been evaluated. Conducting systematic studies of dielectric properties at elevated temperatures is crucial for fundamental characterization and device development, as it allows for the analysis of electrical parameters associated with surfaces, grain borders, or grains.

A series of Ni doped SrNixFe12-xO19 (x = 0.0, 0.05, 0.10, 0.15, 0.20, 0.25) hexaferrites were fabricated through facile micro-emulsion approach and doping content effect was investigated based on structural, dielectric, optical and photocatalytic properties. The prepared materials were characterized via X-ray diffraction (XRD), Raman, Fourier transformed infrared (FTIR), photoluminescence (PL) and UV–vis techniques. The Ni doped SrFe12O19 structure was hexagonal having space group P63/mmc with mean crystallite size in 34–50 nm range. Ferroelectric polarization, coercivity and Remnant polarizations were increased with Ni doping. Dielectric analysis showed the higher values of dielectric parameters with dispersion in low frequency region, which were independent of at high frequency. Optical bandgap was reduced on substitution, which was in 2.31–1.66 eV range, which was in good association with decline in PL analysis. The PCA (photocatalytic activity) of pure SrFe12O19 (SFO) and doped SFNO5 (x = 0.25) material was assessed for removal of crystal violet (CV) dye under visible light illumination. The SFNO5 showed much better PCA and 91 % dye was removed in 90 min with a rate constant of 2.337 × 10-2 min−1 versus pristine SFO (only 55 % with rate constant 8.02 × 10-3 min−1). Results revealed that tuned bandgap and enhanced AC conductivity of doped materials make it crucial candidates for optoelectronic and SOFCs (Solid oxide fuel cell) applications. Owing to the excellent PCA and magnetically separable nature, SrNixFe12-xO19 has potential for the dyes removal from the effluents under solar light irradiation, which could be more economically versus UV based photocatalytic process.

A series of Sr1-xZnxFe1-yNiyO19 with composition of x = 0.0, 0.15, 0.30, 0.45, 0.60 and y = 0.0, 0.2, 0.3, 0.4, 0.5 were prepared using micro-emulsion approach and characteristics were studied by XRD, FTIR and UV–vis techniques. The effect of doping was investigated based on the optical, dielectric, structural and photocatalytic properties of Sr1-xZnxFe1-yNiyO19. XRD analyses confirmed the hexagonal crystal structure of pure and doped SrFe12O19 NPs. The lattice parameters, X-ray density, porosity, bulk density and crystallite size of Sr1-xZnxFe1-yNiyO19 and SrFe12O19 were compared. The FTIR analysis confirmed that there was shifting of peaks from region of lower to higher frequency in Sr1-xZnxFe1-yNiyO19, due to the reduction of the size of grains after doping. The current–voltage I-V data shows that there is gradual increase in the conductivity of as prepared doped-material, but the reverse was the case for resistivity, which exhibit good conducting behavior of the fabricated material. Evaluation of the dielectric properties of the samples shows that the AC conductivity and dielectric constant enhanced, while tangent, dielectric loss and resistivity decreased with concentration of the dopants (Zn and Ni). These excellent properties of doped material can be used for the fabrication of various electronic, electrical, microwave and high frequency devices applications. The photocatalytic activity of Sr1-xZnxFe1-yNiyO19 and SrFe12O19 was tested against methyl green (MG) dye. Results revealed that Sr1-xZnxFe1-yNiyO19 degraded 72.23 % of MG dye in 60 min under the exposure of solar light. The recyclability and usability tests revealed that there was a minute loss after successive four runs. Sr1-xZnxFe1-yNiyO19 might have potential applications as a photo-catalyst under solar light irradiation.

We present a novel estimation method for the moisture absorption rate (MAR) of glass fiber reinforced plastics (GFRPs) using electromagnetic induction testing (EIT). The relationship between the permittivity and MAR were analytically calculated using a simple moisture absorption model. Moreover, we experimentally obtained the magnitude of the displacement current for dielectric specimens with known permittivity values. The equations were derived from the magnitude of the displacement current measured during EIT by combining the analytical and experimental results. To verify the validity of the proposed method using the derived equations, we applied EIT to GFRPs with different MARs. It was found that MAR can be qualitatively evaluated using the proposed method.

This paper investigates the double dielectrics enhancement LDMOS (DDE LDMOS) with high-k field dielectric and low-k buried dielectric. The analytical models of the potential and electric field, optimal breakdown voltage and drift doping concentration are established for this novel LDMOS. The validity of the analytical models is confirmed by the simulation results. Based on the analytical and simulated results, the modulation mechanism of the high-k field dielectric and low-k buried dielectric on the electric field and breakdown characteristics of DDE LDMOS are analyzed and compared. Compared to the conventional LDMOS, the specific on-resistance of DDE LDMOS is reduced by 19%, the breakdown voltage and figure of merit (FOM) of the DDE LDMOS can be improved by 62% and 222.4% when the permittivity of high-k field dielectric and low-k buried dielectric are 100 and 2. Meanwhile, the transfer characteristic, output characteristic, frequency characteristic, and switching characteristic of the DDE LDMOS are also discussed.

The films of alizarin yellow GG (AYGG)–CuCl2 blended with polyvinyl alcohol (PVA) have been successfully synthesized by casting method. The results show that the dielectric properties of AYGG–Cu(II) blended with PVA are enhanced by lowering selected frequency while σac(ω) increases monotonically with frequency, acting in accordance with the correlated barrier hopping model. At low temperature, the DC electrical resistivity of AYGG–Cu(II) blended with PVA film is temperature independent, while it is decreasing with high temperature. Aℓ/(AYGG – Cu(II) blended with PVA)/ITO is fabricated as organic photovoltaic cell, concluding that there are many mechanisms can control the current flow. Aℓ/(AYGG – Cu(II) blended with PVA)/ITO solar cell under illumination of green light be most effective compared to illuminations of others. It is concluded that Aℓ/(AYGG – Cu(II) blended with PVA)/ITO solar cell is very important, with potential advantages such as low cost and low-temperature fabrication processes. It is recommended that this material can be used in different applications such as temperature sensors, inrush current limiters, thermistors, and NO2 sensor.

Bismuth zinc selenide (Bi:ZnSe) thin film was synthesized using electrochemical deposition technique. An aqueous solution of 0.15 mol of ZnSO4•7H2O served as the cationic precursor while the anionic precursor was 0.1 mol solution of selenium metal powder dissolved in 5 ml of hydrochloric acid (HCl) to ensure uniform deposition. The precursor pH was varied at 8, 8.5 and 9. The X-ray diffraction peaks of Bi:ZnSe thin films at different pH were obtained at (220), (221), (300), (310), (311), (222) and (320). The optical band gap energy of Bi:ZnSe thin films grown at pH of 8, 8.5 and 9 decrease from 2.3 – 1.9 eV. The refractive index of Bi:ZnSe grown at pH of 8 and 8.5 exhibited the same thread whereas that of pH of 9 has the highest refractive index.

Spinel ferrites with remarkable electrochemical performance and magnetodielectric (MD) coupling are promising candidates for energy storage and spintronic devices. This study focuses on structural phases, dielectric and magnetic polarization along with magnetodielectric (MD) coupling and electrochemical response of Fe-Cr spinels. Low cost sol–gel method is used to synthesize iron chromite nanopowders. Iron to chromium (Fe/Cr) ratio is varied in the range of 0.2–0.65 (with interval of 0.05). XRD patterns confirm the formation of phase pure FeCr2O4 at Fe/Cr ratios of 0.45, 0.6 & 0.65. Amorphous behavior is observed at Fe/Cr ratios of 0.2, 0.25, 0.5 & 0.55. Mixed phases are observed at 0.3, 0.35 & 0.4 Fe/Cr ratios. Formation of pure spinel phase at Fe/Cr ratio of 0.45 results in high saturation magnetization of 9.2 emu/g. High grain boundary resistance (189.62kΩ) and high dielectric constant (∼83.38 at log f = 5.0) along with low tangent loss (0.00423 at log f = 5) are observed at Fe/Cr ratio of 0.45. Magneto dielectric studies confirm positive magneto dielectric constant (MDC) of synthesized nanopowders at 0.45, 0.6 & 0.65 Fe/Cr ratios. Cyclic voltammetry is performed at constant potential window. Oxidation/reduction process leads to the pseudo-capacitive response of the material. The cyclic voltammetry curves show specific capacitance of 156 Fg−1, 144 Fg−1 and 152 Fg−1 at scan rate of 25 mV/s at Fe/Cr ratios of 0.45, 0.6 & 0.65 of FeCr2O4 nanopowders, respectively. The galvanostatic charging/discharging behavior shows capacitive behavior of FeCr2O4 nanopowders. The electrochemical results suggest that synthesized nanopowders have potential for energy storage system.

High voltage alternating current and high voltage direct current has inspired different authors to concentrate on insulation system, that withstand the rising high voltage level; various researchers have carried out experimental work to prove strength and abilities of transformer oil. This is done by adding different nanoparticles in the oil (Nano fluid) for different transformer applications. In short, this study presents a collection of research studies, which involves preparation of various types of nanomaterial's and their synthetisation. The performance of Nano fluids like electrical breakdown voltage, impulse test and dielectric and thermal behaviour has also been discussed in detail.

Chemical bath deposition (CBD) method, being an electroless technique, is used to prepare phase pure barium titanate (BaTiO3) thin films using glass as substrate. Molarity of the solution is varied from 0.1 to 1.2 M, whereas, solution temperature is kept constant at 78 °C. XRD analyses show formation of perovskite tetragonal phase of BaTiO3 at all the molarities when films are annealed at 300 °C. Strengthening in perovskite tetragonal phase is observed with increase in solution molarity. Ellipsometric results show high transmission (∼ 83 %) in the visible region for thin films prepared with 1.2 M solution. Variation in direct band gap, 3.31–3.61 eV, is observed for annealed thin films. High dielectric constant (∼ 539.26 at log f = 3) and low tangent loss is obtained for 1.2 M based thin films. Thin films prepared under all the conditions show normal and anomalous / U-shaped frequency dependent dielectric response (i.e. ∼ 2754.24 at log f = 1.5 and ∼ 2004.73 at log f = 7.5). Maximum spontaneous polarization of ∼ 14.78 μC/cm2 and remnant polarization of ∼ 6.94 μC/cm2 are observed for 1.2 M sample. It is important to mention here that U-shaped high dielectric and good ferroelectric properties of BaTiO3 are observed in current study with no change in perovskite structure of tetragonal phase making it a potential candidate for storage devices at low and high frequencies.

NASICON-type electrolyte is one of the possible solid-state electrolytes to be employed in solid-state energy devices. The Li1+xAlxSn2-xP3O12 NASICON-based solid electrolyte materials were fabricated using a mechanochemical milling method at 650 °C for 8 h, where x is from 0 to 0.8. From the X-ray diffraction (XRD) analysis, the crystallographic phases of the parent material and the partial aluminium (Al) substituted one have been verified. Site occupancy factor (s.o.f) studies from the XRD data refinement illustrate that the material with x = 0.4 has a stoichiometry in good agreement with the nominal tin (Sn):aluminium (Al) ratio which is 8:2. Field emission scanning electron microscopy (FESEM) was conducted to study the surface morphological properties, revealing the homogenous single-crystalline structure in the sample with x = 0.4, which consists of particles of the smallest crystallite size of 3.77 nm among the samples investigated. The process of partial Al-substitution was further confirmed by the energy dispersive X-ray (EDX). The material with x = 0.4 possesses the maximum conductivity value of 7.57 × 10−6 S·cm−1, which was improved up to 3.79 × 10−5 S·cm−1 by a silver paint treatment. The correlation between the microstructure and the ionic conductivity has been explained via the EDX and impedance analysis results. Ions were found to be the main charge carriers from the transference number analysis (TNM). Variation of relaxation in the dielectric study verifies that Li1+xAlxSn2-xP3O12 obeys a non-Debye characteristic. Patterns of the dielectric results strengthened the trend of ionic conductivity.

SnFe2O4 nanoparticles have found wide applicability in recent times. An investigation of the thermal behaviour is important for its utility in dielectric/energy applications that involves heat treatment. The present work reports the synthesis of SnFe2O4 nanoparticles and the investigation of the thermal stability, magnetic and electrical properties on annealing. SnFe2O4 nanoparticles were synthesized by the solvothermal method and characterized using Thermogravimetry, X-ray diffractometry, Scanning and Transmission Electron Microscopy and Vibrating Sample Magnetometry. The spinel structured SnFe2O4 nanoparticles showed superparamagnetic behaviour with MS = 10.5 emu/g and paramagnetic transition at 517°C. On annealing in air between 300°C and 1100°C, the spinel phase was found to be stable until 500°C, but decomposed to tetragonal and hexagonal Fe–Sn oxides beyond 550°C. The resultant oxides were antiferromagnetic or weakly ferromagnetic. Electrical measurements revealed large dielectric constant (∼104) and dielectric loss

This paper provides a detailed report on the effect of molar concentration on structural, optical and electrical properties of cobalt doped zinc selenide (ZnSe:Co) thin film. The molar concentration Co dopant was varied within 0%, 0.1%, 0.2% and 0.3%. ZnSe:Co was synthesized using the electrodeposition method. Different characterization techniques such as X-ray diffractometry, scanning electron microscope and four-point probe were used to study the optical, surface morphology and electrical properties of ZnSe:Co. The XRD analysis revealed that both Co-doped and undoped ZnSe are crystalline materials. The crystalline structure of ZnSe is cubic but changes to a face-centred cubic structure upon introduction of Co dopant. ZnSe:Co showed excellent absorbance, optical conductivity and refractive index. The energy bandgap was observed to decrease from 2.2 to 2.0 ​eV as the molar percentage increased from 0.1 to 0.3%. The conductivity of the cobalt doped Zinc selenide was observed to be 1.4244 ​× ​1011, 1.6655 ​× ​1011, 1.6655 ​× ​1011, and 2.4929 ​× ​1011 (S/m) for film grown with 0%, 0.1%, 0.2% and 0.3% Co dopant respectively.

We synthesized strontium titanate SrTiO3 (STO), Zr doped Sr1−xZrxTiO3 and (Zr, Ni) co-doped Sr1−xZrxTi1−yNiyO3 samples using solid state reaction technique to report their structural, electrical and magnetic properties. The cubic Pm-3m phase of the synthesized samples has been confirmed using Rietveld analysis of the powder X-ray diffraction pattern. The grain size of the synthesized materials was reduced significantly due to Zr doping as well as (Zr, Ni) co-doping in STO. The chemical species of the samples were identified using energy-dispersive X-ray spectroscopy (EDX). The Zr and Ni dopants’ homogeneity were confirmed from EDX mapping to negate spurious ferroic order due to dopant segregation. We observed forbidden first order Raman scattering at 148, 547 and 797 cm−1 which may indicate nominal loss of inversion symmetry in cubic STO. The absence of absorption at 500 cm−1 and within 600–700 cm−1 band in Fourier Transform Infrared spectra corroborates Zr and Ni as substitutional dopants in our samples. Due to 4% Zr doping in Sr0.96Zr0.04TiO3 sample dielectric constant, remnant electric polarization, remnant magnetization and coercivity were increased. Notably, in the case of 4% Zr and 10% Ni co-doping we have observed clearly the existence of both FE and FM hysteresis loops in Sr0.96Zr0.04Ti0.90Ni0.10O3 sample. In this co-doped sample, the remnant magnetization and coercivity were increased by ∼1 and ∼2 orders of magnitude respectively as compared to those of undoped STO. The coexistence of FE and FM orders in (Zr, Ni) co-doped STO might have the potential for interesting multiferroic applications.

Polyaniline-chitosan (PANI-Cs) blends were prepared by in situ oxidative polymerization with acetic (CH3COOH) acid and hydrochloric (HCl) acid as dopants. Using Fourier transform infrared (FTIR) spectroscopy, the C N and C C stretching of quinoid and benzenoid of PANI in the PANI-Cs blends was confirmed at ranges 1528cm−1 to 1571cm−1 and 1490cm−1 to 1493cm−1, respectively. PANI emeraldine state was stipulated in all samples and PANI-Cs HCl samples have the highest degree of oxidation which is 48.56±0.23%. The ultraviolet-visible (UV–vis) spectroscopy identified the glucopyranose of Cs (282–308 nm), and π−π* transition of benzenoid (389–437 nm) and quinoid rings (551–554 nm) of PANI. The PANI-Cs blends yielded optical band gap values of 1.968±0.014 to 2.009±0.005 eV due to the presence of PANI. One-way ANOVA was also performed, and results showed the significant effect of using different dopants towards the degree of oxidation of the samples. Frequency dependent behavior was observed to the PANI-Cs samples with AC conductivity values around 1.2–4.1 Scm−1 at 105–107 Hz. The 102 Hz dielectric peak intensity of the samples varied due to influence of dopants on charge polarization. Lastly, PANI-Cs samples showed dominance of DC loss and relaxation at low frequencies 10–103 Hz.

Here, we study the structural relaxation kinetics in modified binary (i.e., ternary) mixtures with strong concentration fluctuation imposed by a polar picoline and an apolar triphenylethylene by adding a surfactant phenanthridine. The dielectric and enthalpy relaxation measurements are applied to monitor the dynamic properties aiming at distinguishing various effects of the concentration fluctuation. It is found that the strong concentration fluctuations are largely suppressed by adding the surfactant molecule. However, compared with the binary mixtures, a larger difference in the glass transition temperatures determined by the dielectric and enthalpy methods is observed in some of the ternary mixtures. Another unusual behavior in the ternary mixtures is that the enthalpy relaxation produces higher non-exponential factor β than the dielectric relaxation. The comparison of various parameters confirm that the reduced glass transition width is more suitable for characterizing the strength of concentration fluctuations in multi-component systems.

Sr-doped lanthanum cobaltite (La1−xSrxCoO3) perovskite oxides with × = 0.0, 0.20, 0.50, 0.80 were prepared using the modified sol–gel method at 600 °C. The synthesized Sr-doped LaCoO3 perovskite oxides (x = 0.0 and 0.20) crystalize as rhombohedral structured materials, while La0.2Sr0.8CoO3 perovskite oxide (x = 0.80) crystalizes as primitive cubic structured material as also confirmed by Rietveld refinement using x-ray diffraction. Moreover, the synthesized materials were investigated in details using fourier-transform infrared spectroscopy, scanning electron microscopy, energy dispersive studies and x-ray photoelectron spectroscopy techniques. The electrical conductivity of the perovskite oxides was improved through the substitution of La by Sr. Frequency dependent dielectric properties (dielectric constant and dielectric loss) of La1−xSrxCoO3 perovskite oxides were also investigated in frequency range from 20 Hz to 3 MHz at room temperature. Dielectric constant and dielectric loss of La1−xSrxCoO3 perovskite oxides decrease at low frequency, while it was found to be constant at high frequency.

Indium doped GaFeO3 (Ga1-xInxFeO3, 0 ≤ x ≤ 0.25) samples were synthesized by the ceramic’s procedure. The correlation between lattice parameter, different ions occupancies between different sites and the octahedral and tetrahedral distortion of indium doped GaFeO3 were studied in detail. Zero field cooled (ZFC) and field cooled (FC) magnetization measurements revealed that all samples exhibited a ferrimagnetic to paramagnetic phase transition below room temperature. Applying the law of approach to saturation, the 10% indium doped GaFeO3 sample revealed the highest saturation magnetization than the other samples. The dielectric constant (ε,), dielectric loss (tanδ), ac-conductivity, complex impedance parts and the hopping probability of electrons variation with temperature and frequency were studied in detail at different values of indium doping in GaFeO3 sample. The influence of doping on the activation energy of the conduction process was also investigated. Impedance Nyquist plot was used to differentiate between the grain and grain boundary contribution in indium doped GaFeO3 samples.

The YCr0.5Fe0.5O3 ceramics with different sintering temperatures (TS) have been synthesized by a sol-gel method, and the structural, magnetic and dielectric properties are studied. With the decrease of TS, continuous decrease of grain size is evidenced via the micromorphology analysis. Due to the competition between the single ion magnetic anisotropy and the antisymmetric Dzyaloshinsky-Moriya interaction, the total magnetization becomes zero at the compensation temperature (TComp) in the presence of a lower magnetic field, and the TComp exhibits size dependent behavior. With the decrease of grain size, the TComp becomes lower due to the increase of uncompensated spins. Meanwhile, the TComp is adjustable by the magnetic field, and a larger external field drives the TComp to lower temperature. After cooling the samples in magnetic field, the magnetic anisotropy is established, which results in a positive exchange bias (EB) effect below the TComp. The decrease of TS would increase the ferromagnetic component, which leads to the decrease of EB field (HEB). The dielectric measurements suggest that the samples of TS = 900 and 800 °C possess large permittivity accompanied with dielectric relaxation near room temperature, and the dielectric relaxation which arises from the single-ionized oxygen vacancies moves to higher temperature with the decrease of TS.

In the present investigation, La1−xGdxCr1−yFeyO3 nanoparticles were synthesized using facile micro-emulsion technique and monitored by XRD (X-ray diffraction), VSM (vibrating sample magnetometer), SEM (scanning electron microscopy), EDS (energy dispersive spectroscopy) and dielectric measurements. XRD analysis revealed the effective exchange of Fe and Gd ions into the regular structure of LaCrO3 and La1−xGdxCr1−yFeyO3 have orthorhombic crystal structure and crystallite size was in 30.20–34.1 nm range. The particles were of flakes morphology and EDX analysis revealed the purity and Fe and Gd ions incorporation into the structure of LaCrO3 and La1−xGdxCr1−yFeyO3. The magnetic hysteresis loop showed the paramagnetic behavior at room temperature and dielectric properties of La1−xGdxCr1−yFeyO3 were significantly affected with Fe and Gd contents. The PCA (photocatalytic activity) was performed against MB (methylene blue) dye under visible light exposure and up to 68% MB dye destruction was observed within 45 min of exposure. Results revealed the LaCrO3 properties are tunable with Fe and Gd doping to prepare catalyst active under solar light exposure.