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AbstractPolymer-based composites are highly regarded as favorable candidate materials for dielectrics in high-energy-density capacitors, owing to their exceptional flexibility and fast charge-discharge capabilities. Recently, multilayer-structured polymer composites have gained significant attention as a promising solution for energy storage and dielectric applications, offering a combination of high energy density and low dielectric loss. These polymer multilayer films, comprising two or more layers synthesized through specific fabrication processes, have presented extensive uses in various applications, including packaging and optical materials, such as oxygen barrier, holographic anti-counterfeiting, and optical sensing, due to their versatile and tunable functionalities. The distinctive chemical composition and structural design of these layers, whether symmetrically or gradient distributed, endow these dielectric composites with superior integrated electric properties. This review provides a comprehensive overview of fabrication methods and strategies employed in the latest advancements in dielectric multilayer-structured polymers for energy storage applications. It delves into the design and manufacturing techniques of advanced multilayer composites, highlighting the diverse strategies utilized to enhance energy performance, such as polarization manipulation, electric field distribution control, interfacial modification, and geometric confinement of interfaces within both organic and organic/inorganic multilayer-structured composites. Lastly, this review addresses the current challenges and future prospects in the development of multilayer composites with enhanced energy storage performance. [ABSTRACT FROM AUTHOR]

The current transition to the electric car by all users is advancing steadily, and hence the design of these products occupies a prominent place in the car design sector. Likewise, the user experience is one of the determining aspects for the choice of a model. The main objective of this work is to determine, through eye tracking, which areas of an image (in this case, images of the front of cars) are more influential in the perception of the vehicle as either electric or combustion-powered, by segmenting the most important areas of a vehicle and users' perceptions thereof according to gender and other socio-demographic variables. This work provides an experimental design and a way to analyse and draw conclusions from an oculometry study for vehicles, as well as an initial design briefing for the generation of the visual identity of electric vehicles based on the perception of users for different elements of the vehicle. A methodology is proposed that includes the use of tools such as ANOVAs, eye-tracking, heat maps, tracking maps and fixation times. Through this data it is possible to develop optimal designs aligned with the user's perception. [ABSTRACT FROM AUTHOR]

Bamboo has low-cost, fast-growing, good mechanical properties, and its cultivation results in environmental benefits such as CO2 sequestration and preservation of native forests, in addition to being an excellent source for natural fibers. Bamboo fiber presents high mechanical performance, which can be further improved by chemical or physical treatments. Controlled pyrolysis is an important treatment for modifying natural fibers, generating materials with different properties. In the present study, bamboo fibers from the species Dendrocalamus asper were subjected to controlled pyrolysis at 160, 400, and 800 °C and their morphological, thermal, and electric properties were evaluated by thermogravimetric analysis, X-ray diffraction, scanning electron microscopy, molecular absorption test, and electrochemical impedance spectroscopy. Controlled pyrolysis at 160 °C caused few changes to the structure and properties of the bamboo fiber. However, thermal stability, crystalline structure, and fiber morphology were strongly affected during pyrolysis at 400 and 800 °C. A resistive electric behavior was also verified in the fiber pyrolyzed at 800 °C, while for the other treated fibers, a capacitive electric behavior was verified. The controlled pyrolysis of bamboo fibers proved to be viable for producing new fibers with different properties. [ABSTRACT FROM AUTHOR]

Ferroelectric ceramics display a remarkable photostriction effect, which could facilitate the prevention of electromagnetic interference and promote the integration and miniaturization of actuator systems, indicating potential applications in glimmer sensors. In this work, highly transparent La-doped 0.9Pb(Mg1/3Nb2/3)O3-0.1PbTiO3 (0.9PMN–0.1PT) ceramics were synthesized using a solid-state reaction method in an oxygenated atmosphere. XRD and SEM were used to analyze the phase structure of the dense samples, which displayed a pure perovskite structure, with no trace of a pyrochlore phase. With La doping, the phase transition temperature shows a decreasing trend, and its dielectric constant could reach up to 20,000. The P-E loop of the samples was gradually refined into a straight line with an increase in the doping amount. After La doping, the transparency of the 0.9PMN–0.1PT ceramics was significantly enhanced and reached up to 61% at the near-infrared band. Finally, the photogenerated voltage and deformation of the La-doped 0.9PMN–0.1PT ceramics were investigated under ultraviolet light of various intensities. After 20 s of irradiation at an intensity of 800 mW/cm2, the maximum voltage and deformation, with values of 40 V and 250 nm, respectively, were both found in the 1%La-doped 0.9PMN–0.1PT ceramics. [ABSTRACT FROM AUTHOR]

Designing Solid-State Electrolytes (SSEs) exhibiting high ionic conductivity and high mechanical/thermal stability is the main concern for developing next-generation rechargeable batteries. Here we present the successful synthesis of colorless, transparent, and bubble-free phosphate glasses with high lithium-ion electrical conductivity within the system xLiCl–(1–x)(63Li2WO4–37P2O5) with 0 ≤ x ≤ 30 mol%. The structural study is performed using Raman spectroscopy. Electrical conductivity measurements of the glasses are investigated over a large frequency range at various temperatures using impedance spectroscopy. It is found that the electric conductivity increases with increasing lithium chloride content. The dc conductivity reaches 2.76 × 10−6 (Ω−1.cm−1) at room temperature (RT) for the glass (x = 30 mol%). The frequency dependence of the conductivity is investigated and the scaling of the conductivity spectra shows that the conduction mechanism in the glasses is both temperature and composition-independent. [ABSTRACT FROM AUTHOR]

BaBi4Zr2Sn2O15, a modified ceramic sample belonging to the oxide family of layered ferroelectrics, is synthesized using the mixed oxide process after firing for calcination at 810 °C for 6 hrs. XRD study of the compound exhibits the growth of an orthorhombic single-phase structure at atmospheric temperature. The electrical properties of the sample are investigated in a broad temperature range (30–500 °C) and frequency range (100 Hz - 106 Hz). The dielectric properties recommend the transition from ferro to paraelectric state at 410 °C which is much more than room temperature. The impact of frequency and temperature on complex immittance parameters (impedance and modulus) are analyzed by an impedance analyzer in broad frequencies and temperature ranges. The electrical properties show; (i) the existence of semiconductor-like negative temperature coefficients of resistance behavior, (ii) evidence of electrical relaxation phenomena as a function of temperature, and (iii) the existence of single electrical relaxation ascribed to the existence of grain contribution to the electric properties. [ABSTRACT FROM AUTHOR]

Potassium sodium niobate (KNN) is an environmentally compatible piezoelectric material for substituting harmful lead-based ceramics. KNN-based ceramics have excellent piezoelectric properties with high Curie temperature. But, KNN faces difficulties during the processing like volatilization of alkali elements, chemical inhomogeneity, low densification, etc. The objective of this research is to investigate the impact of certain metal oxides additions like ZnO and MnO2 as sintering aids to solve the problems of the preparation and hence study the structural and electric properties of K0.5N0.5NbO3 (KNN) ceramics. ZnO and MnO2 added potassium sodium niobate, K0.5N0.5NbO3 was prepared by using the ceramic method. The prepared samples were sintered at 1000 °C for 2h conventionally. The structural properties of the ceramics have been analyzed by using X-Ray Diffractometer. The study demonstrates the formation of the orthorhombic-symmetric perovskite phase in all the prepared samples. The microstructural behavior of the ceramics has been characterized by techniques such as scanning electron microscopy (SEM) and compositional properties were studied by energy dispersive x-ray (EDAX). The effects of metal oxide additions on the electronic properties such as dielectric constant, dielectric loss, impedance properties, Nyquist plot, etc., were studied. The results have been analyzed and discussed in the paper. [ABSTRACT FROM AUTHOR]

Lead-free Ba(Ti0.91Sn0.09)1-xVxO3 (BTSV, x = 0, 0.005,0.010, 0.015, and 0.020) ceramics were prepared by the conventional solid-state sintering method with a calcination temperature of 1200 °C for 2 h and a sintering temperature between 1350 °C and 1400 °C for 4 h. The effect of vanadium (V) doping on the phase formation, microstructure and electrical properties of the ceramics was investigated. X-ray diffraction (XRD) measurements revealed that the ceramics with x = 0 and 0.005 had pure perovskite structures with no detectable impurity, while the ceramics with x ≥ 0.010 exhibited perovskite structures and had secondary impurity phases. Coexisting orthorhombic and tetragonal phases were observed and the Rietveld refinement analysis suggested that the tetragonal phase increased with increased V5+ substitution. When x increased from 0 to 0.010, the average grain size increased from 47 to 62 µm and then dropped, while the density (ρ) decreased from 5.98 to 5.64 g/cm3 when x increased. Furthermore, the BTSV ceramics exhibited increased porosity, Curie temperatures (TC ∼ 42 °C to 52 °C) and coercive field (Ec), while the dielectric constant at the Curie temperature (εC) and the remnant polarization (Pr) of the ceramics decreased (∼18023 to 6110 and ∼7.42 to 4.88 µC/cm2, respectively) when V5+ doping increased. [ABSTRACT FROM AUTHOR]

We study the transverse normal linear propagating modes within a cylindrical wave guide filled with a blue-phase liquid crystal, which is subjected to the cladding by means of soft anchoring boundary conditions. The axis of the two dimensional helical structure of the blue phase is taken parallel to the cylindrical wave guide axis. We establish the coupled governing equations consisting of the electromagnetic Maxwell's equations in the presence of a blue phase and the equilibrium equations for the blue-phase texture resulting from the minimisation of both, the bulk and surface free energy. By assuming a low intensity electromagnetic field, we decouple the texture equation and solve it to obtain blue-phase configurations; parameterised for different anchoring energies from which calculate the band structure and electromagnetic fields associated to these textures. We find that the number of propagating modes in the blue-phase cored waveguide depends on the anchoring strength. [ABSTRACT FROM AUTHOR]

In this paper, the promising way to utilize EAF (electric arc furnace) slag as a cementitious material has been studied by employing microbially accelerated carbonation technology. Under the conditions of cation supplementation and accelerated carbonation of bacteria, the highest compressive strength of the samples could achieve 18 MPa in this research. The changes in minerals and microstructures during the carbonation and microbial carbonation have been observed by X-ray diffraction (XRD), thermogravimetric analysis (TG), and mercury intrusion porosimetry (MIP). Carbonic anhydrase-producing microorganisms have obvious acceleration effects in the carbonation process, making the matrix compact and improving the mechanical properties. Besides, the treatment method of accelerating carbonation by microorganisms could effectively inhibit the leaching of heavy metals in the EAF slag. This paper provides a reference for the potential applications of EAF slag in engineering and reveals the mechanism of microbial acceleration. Industrial waste electric arc furnace (EAF) slag was used as a cementitious material and could fix carbon dioxide. Microbial technology promotes the deposition of calcium carbonate (1–5 μm) to fill pores over 1 μm. Microbial accelerated carbonated EAF bricks could reduce the leaching of heavy metals. [ABSTRACT FROM AUTHOR]

Zn-doped and un-doped BCTO ceramics (Bi2/3Cu3−xZnxTi4O12, x = 0 and 0.05) were prepared by chemical route sintered at 1123 K for 8 h. The Phase formation of ceramics were confirmed by X-ray Diffraction. Their microstructural properties were examined through SEM, EDX, and TEM. The dielectric constant (ɛr) of BCTO ceramic was obtained higher than BCZTO-0.05 ceramics at 100 Hz and 470 K. The tangent loss (tan δ) value for Zn doped BCTO ceramics were found to be lower than undoped BCTO ceramics at 10 kHz and 310 K. The conductivity dependence of Bi2/3Cu3−xZnxTi4O12 ceramics (where x = 0, 0.05), with the inverse of temperature follows the Arhenius equation, with a major temperature range of 300–500 K. [ABSTRACT FROM AUTHOR]

A comparison study of pure barium titanate BaTiO3, dipole-pair [Ga3+, Ta5+] substituted barium titanate Ba(Ga3+, Ta5+)0.005Ti0.99O3 ([Ga3+, Ta5+]: BaTiO3), single ion [Ga3+] substituted barium titanate Ba(Ga3+)0.01Ti0.99O3 ([Ga3+]: BaTiO3), and single ion [Ta5+] substituted barium titanate Ba(Ta5+)0.01Ti0.99O3 ([Ta5+]: BaTiO3) ferroelectric ceramics have been conducted in order to discern the unique electric and dielectric properties derived from dipole-pair substitution. The band gap, DC resistivity, relative permittivity, dissipation factor, and complex impedance have been measured and analyzed. The dipole-pair substituted material is demonstrated to be an excellent dielectric, which possesses high electrical resistivity, high activation energy, significant dielectric diffuseness, high relative permittivity and low dissipation factor, due to charge compensation and creation of dipole-pairs in barium titanate solid solution ceramic matrix. The single substituted (acceptor and donor, respectively) samples behave more like traditional semiconductors, which have lower electrical resistivity, lower activation energy, and exhibit strong dielectric anomaly and large dissipation factor due to charge imbalance (electrons and holes) in part compensated for through additional defect creation. The relaxor-like behavior of the dipole-pair substituted sample is distinguishable from the classic relaxor through electric properties and structural phase diagram and is anticipated to spark more attention and further exploration. The unique features of electric resistivity and dielectric diffuseness of the dipolar-pair engineered BaTiO3 affords opportunity for designing properties of novel relaxor-like ferroelectrics. [ABSTRACT FROM AUTHOR]

Soft and hard composites of ferrites with compositional formula (NiFe2O4)100-x – (BaFe12O19)x (where x = 0,20,50,60,80,100) were prepared using sol-gel method. The samples were calcined individually at 900 °C and composites in the required proportions were sintered at 1100 °C in a conventional furnace. The coexistence of NiFe2O4 and BaFe12O19 composites has been confirmed by the X-ray diffraction studies and found to be without any impurities. Rietveld analysis of X-ray diffractograms corroborates hexagonal phase with P63/mmc space group for Barium hexaferrite and cubic phase with Fd-3m:2 space group for Nickle ferrite. The surface morphology was investigated by scanning electron microscopy (SEM), and the micrographs are observed to indicate well distributed grains in the exchange coupled composites. Grains of nano-size about 100–300 nm are formed for the composites. The magnetic properties have been studied by VSM and electric properties were studied by measuring the dielectric constant at room temperature. UV; FTIR studies of the samples are exhibiting fundamental absorption bands. [ABSTRACT FROM AUTHOR]

The features of electric transport in the powder samples consisting of the nanosize 2D-MoS2 flakes with different number of layers have been studied under the conditions of uniaxial pressure. There have been measured current-voltage characteristics at the room temperature in the voltage range of 0 through 1.5 V at three magnitudes of the uniaxial pressure from 0.5 through 2.5 MPa. The current-voltage characteristics are shown to be non-linear and to form a loop during successive increasing and decreasing voltage. The long-term decays of the current on applying voltage to the sample and of the voltage on the sample in the no-load mode on switching off have been observed. The observed results are explained by the model of the surface charge accumulation causing polarization. [ABSTRACT FROM AUTHOR]

The features of electric transport in the powder samples consisting of the nanosize 2D-MoS2 flakes with different number of layers have been studied under the conditions of uniaxial pressure. There have been measured current-voltage characteristics at the room temperature in the voltage range of 0 through 1.5 V at three magnitudes of the uniaxial pressure from 0.5 through 2.5 MPa. The current-voltage characteristics are shown to be non-linear and to form a loop during successive increasing and decreasing voltage. The long-term decays of the current on applying voltage to the sample and of the voltage on the sample in the no-load mode on switching off have been observed. The observed results are explained by the model of the surface charge accumulation causing polarization. [ABSTRACT FROM AUTHOR]

Residential clothes drying consume about 650 TBtu of primary energy per year in the United States, equivalent to 3% of primary residential energy consumption. There is a strong impetus to reduce the energy consumption of clothes dryers by both improving existing technology and developing alternatives that use fundamentally different drying mechanisms. Clothes drying technologies are broadly classified into either evaporative or mechanical drying. The focus of this paper is on mechanical drying, including vibrational, centrifugal, and press-based methods. In this work, the physical processes involved in these mechanical fabric drying processes were analyzed to develop general theories of mechanical cloth drying energy efficiency. Quantitative evaluation of the theories requires measured fabric properties. To accomplish this, a set of experiments was conducted on samples of a standard test fabric. The fabric was a cotton-polyester blend specified by the US Department of Energy to evaluate the standardized efficiency of all residential clothes dryers in the US. Mercury porosimetry experiments were conducted to determine the fabric pore size distribution, apparent density, and porosity. Elasticity experiments were conducted to determine the fabric's Young's modulus. Isostatic press experiments were conducted to establish a relationship between compression force and fabric moisture content. The data resulting from these experiments were combined with mathematical models developed in this work to calculate the theoretical maximum performance limits for mechanical drying of the standard fabric. The results of the analysis are used to make recommendations for the most promising technologies that offer the greatest potential energy savings for residential clothes drying. [ABSTRACT FROM AUTHOR]

The present work investigates microstructural, structural, ferroelectric and dielectric properties of Holmium, Ho3+, doped SrBi4Ti4O15 (SBT). Polycrystalline ceramics (SrBi4-xHoxTi4O15 SBHT, where x = 0, 0.02. and 0.03) were prepared by solid-state reaction method using high energy planetary ball mill. The surface morphology of all samples displayed dense microstructure and average grain size decreased with Holmium content increase. The XRD results of samples confirmed a single phase of SBT with orthorhombic crystal structure and a reduction in unit cell volume with the substitution of Holmium at B-site. The improvement in the structural and microstructural properties greatly enhanced the electric properties of SBHT. SBHT (x = 0.02) sample showed the improved ferroelectric properties (remnant polarization Pr = 1.63 μC/cm2 and Coercive field Ec = 0.51 kV/cm) making them suitable for ferroelectric applications. High Curie temperature (TC = 626 °C), elevated dielectric constant (εr = 236) and low loss (tanδ = 0.062) are obtained with the substitution of Ho (for x = 0.03) at B- site of SBT. These ceramics have high TC and improved thermal stability which makes these apt for the applications in high temperature sensors. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the field performance of the piezoelectric-based energy harvesting pavement system (PZ-EHPS) under moving traffic loads by multi-physics modelling. Finite element models (FEMs) with multiple physical interfaces were built with the close circuit system. The laboratory scale of FEM was analysed to validate the voltage output as compared to the measurements in laboratory tests. To enhance the computational efficiency of large-scale simulation, a homogenisation approach was developed to convert the piezoelectric composite layer to the homogeneous layer with equivalent mechanical and electric properties. The variations of power output patterns from the PZ-EHPS, with different geometric designs under different traffic loading levels and temperature conditions, were studied. The results show that the width of the PZ-EHPS shall match the wheel path to generate electricity and avoid energy consumption in the area uncovered by traffic loading, during the electricity transmission. The power output of the PZ-EHPS shows an exponential relationship with the increase of load magnitude from vehicles. Future studies are needed to achieve the full utilisation of each function layer for building smart pavement with multiple functions. [ABSTRACT FROM AUTHOR]

The various properties of ferroelectric ceramics bring extremely rich colors to life. Its various properties such as dielectric properties, electromagnetic properties, and anti-magnetic interference properties have been successively studied in various fields, except for stone carvings, outdoor environmental sculptures, ornamental ceramics, etc. Because of its superior performance, it can also be used in aircraft manufacturing, anti-interference materials for train tracks, and can even realize unmanned driving, workshop networks and other environments, which can meet the normal operation of electronic equipment in the car under the state of preventing external electromagnetic interference. This requires the superior electromagnetic properties of ferroelectric ceramics. Dielectric properties, dielectric relaxation, and ferromagnetic effects all need to be optimized. This article first introduces the performance test methods of ferroelectric ceramics, and describes the dielectric relaxation through Debye equation He phenomenon, test dielectric loss and dipole interaction, magnetic coupling effect and multiferrocity, and carry out electromagnetic coexistence, based on MATLAB/Simulink rail vehicle dynamics model, composed of sensors, control center and bogie, forming a coupling The functioning anti-roll structure makes the magnetic potential energy evenly distributed in the track span, forming a single suspended electromagnet modular transportation train dynamic model, which can carry the load force of the air and the gravity of the module itself. The traditional solid-phase method is used to dope at the A site. As the doped sample gradually increases, the peak value of the derivative peak changes, causing the original diamagnetic sample to carry a certain degree of ferromagnetism, and the doping amount and ferromagnetism are positively correlated. Then, experiments were performed on the composite ferroelectric ceramic materials doped with ion pairs, and the tests were carried out at different temperatures and different doping amounts. The conclusions about the coupling of dielectric constant, dielectric loss, magnetic properties and magneto electric properties were obtained and obtained the anti-magnetic interference ability. The application in the anti-magnetic interference of rail trains has a certain guiding effect. The results show that when the doping amount reaches m = 0.02, the dielectric loss is reduced by 22.58 times. The impedance change rate of the ferroelectric ceramic material with no doped Al3+-Li + ion pair under 9 kOe is 3.95%, while at m = 0.015 Al3+ With -Li + doping, the impedance change rate of ferroelectric ceramics is 14.45%, which is 3.17 times the original. [ABSTRACT FROM AUTHOR]

In microwave (MW) drying, the adjustable incident MW power is preferred to improve the product quality and reduce energy consumption. However, the control of incident MW power during the drying process is still a challenging task. By comparing continuous and intermittent microwave drying with gradually reduced microwave power, a control strategy in microwave drying of the green turnip taproot was proposed, based on the experimentally determined dielectric properties and the variation of the electric field intensity with temporal moisture content. The experiments show that such a power control results in higher rehydration ratio of dried green turnip and reduction in energy consumption than these in the continuous and intermittent microwave drying. Moreover, such a power control strategy can maintain the material temperature within the set values with low fluctuations. [ABSTRACT FROM AUTHOR]

Lead-free (Ba0.85Ca0.15)(Ti0.90Zr0.10)O3-xNiO (x = 0, 0.2, 0.4, 0.6 and 0.8 wt%) ceramics were prepared by the solid-state combustion technique using glycine as a fuel. The effect of NiO doping on the phase formation, microstructure, electrical and magnetic properties of the ceramics was investigated. The powders and ceramics were calcined and sintered at a temperature of 1050 °C and 1450 °C for 2 h, respectively. XRD results showed that all ceramics had coexisting orthorhombic and tetragonal phases. Increasing the amount of NiO doping enhanced the amount of tetragonal phase, as verified by the Rietveld refinement technique. The density values (ρ) and the average grain size rapidly decreased from 5.79 to 4.69 g/cm3 and 37.8 ± 3.6 to 3.0 ± 0.3 µm when NiO doping increased from 0 to 0.8 wt%. The values of the dielectric constant (ε), dielectric loss (tan δ) and remnant polarization (Pr) tended to decrease when NiO doping increased. Only the sample with 0.4 wt% NiO exhibited ferromagnetic behavior at room temperature, with a remnant magnetization (Mr) and a coercive field (Hc) of 1.04 × 10−5 emu/g and 72.55 Oe, respectively. [ABSTRACT FROM AUTHOR]

In the past few years fluoroperovskite have gained an immense interest by researchers and making it a hot candidate for optoelectronic applications. In this work, first time, we have computed the structural, electronic and optical properties of pure and Be/Sr-doped fluoroperovskite KMgF3. The structural stability is analysed by calculating optimised lattice parameters of pure and doped (1.04%, 4.22% and 7.04%) KMgF3. The structural results show the phase transformation from cubic to body centre Aa tetragonal structure. The band gap of pure KMgF3 is indirect, at G and R symmetry points, which converted to direct band gap, at G symmetry point, after doping at all doping concentrations. The anomalous behaviour of Be decreases the band gap from 6.135 to 2.469 eV and the insulating behaviour is transformed to semi-conducting nature. While in Sr case, the band gap decreases (6.153–5.446 eV) but the nature of the compound remains insulating. The optical properties like absorption, refractive index, reflection, loss function and extinction coefficient are computed from the complex dielectric function. The study of electric and optical properties will give the basis for future applications of KMgF3 in optoelectronic devices. [ABSTRACT FROM AUTHOR]

The dielectric properties and the hysteresis electric cycles of a monolayer stanene-like nanostructure are studied using Monte Carlo simulations. The considered system consists of mixed spins S= ±1 and σ= ±7/2 with an ferrielectric intermediate exchange coupling. We start by analyzing the ground state phase diagrams for (T = 0). In this case, only 18 configurations are stable among 8 × 3 = 24 possible ones. Besides, for T > 0, we investigate the behavior of the blocking temperature for different electric parameters. We discuss the polarization plateaus of the hysteresis electric cycles of this nanostructure by exploring the critical (EC), the coercive (ECoer), and the saturation (ES) electric fields. [ABSTRACT FROM AUTHOR]

Ferroelectric Bi3.25Nd0.75Ti3O12 (BNT), BiFeO3 (BFO) and Bi3.25Nd0.75Ti3O12-BiFeO3 (BNT-BFO) composite thin films were deposited onto Pt/Ti/SiO2/Si(100) substrates using the sol–gel process. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to identify the crystal structure, the surface and cross-section morphology of the deposited ferroelectric thin films. Structure evolution and ferroelectric properties of the as prepared thin films annealed under 750 °C were studied in detail. It is found that the leakage current of the entire thin film was effectively reduced by preparing BNT and BFO composite thin films with appropriate thickness ratios to achieve their full advantages, and consequently, significantly improve the ferroelectric properties of the composite thin films. [ABSTRACT FROM AUTHOR]

A number of the nanocarbon-metal Nix-C and Co50-C core–shell structures were obtained from phenol-formaldehyde resin as a carbon precursor using a mechanochemical method and pyrolysis at 1034 °K. The morphology of the obtained core–shell structures was characterized by scanning electron microscopy. The magnetic hysteresis loops of Ni25-C and Co50-C core–shell structures were investigated by using a vibrating sample magnetometer. The work presents the results of investigations of electrical resistivity of nanocarbon-metal Nix-C and Co50-C core–shell structures embedded in polyvinyl acetate (PVA). Electrophysical properties of the composite materials (CMs) have been studied in a wide temperature range: 77–293 K. It was found that morphology and composition (the content of the metal phase and its relation to the carbon phase) of Nix-C core–shell structures embedded in PVA influences the value of electrical resistivity, its temperature dependence ρ(Т) and δρ/ρ parameter of composites. The materials with the higher content of core–shell structures (Ni75-C and Co50-C) are characterized by the lower electrical resistivity, while the materials with the significant content of separate carbon phase in the form of nanotubes are characterized by the weaker ρ(Т) dependence. [ABSTRACT FROM AUTHOR]

In this contribution, we show that the product dissociation energy (D) × interatomic distance (R) with regards to a straightforward taxonomy of diatomic molecules comes to assume a relatively high and virtually constant value. It is so much so that the heavier the diatomic molecules at hand, the closer DxR approaches e2(where e is the elementary charge intensity in esu). This occurrence is studied herein separately under families arranged from chemically-alike diatomic molecules. Each family (such as the set made of 'pairs of strictly alkali atoms', or 'pairs of strictly halogen atoms', or 'pairs of alkali-halogen atoms', etc), is thus composed of diatomic molecules formed of atoms bearing similar electronic configurations; whereby we initially ended up dealing with 18 families in total. In addition to those, we brought together 10 more families of diatomic molecules each composed of heavy metal atoms belonging respectively to each of the ten columns drawn from the three rows of heavy metals under the Periodic Table, and observed an even better conformance. [Sc2, Y2, La2] is the first family in question; [Ti2, Zr2, Hf2] and [Va2, No2, Ta2] are the next two families; [Zn2, Cd2, Hg2] delineates the last family of heavy metal diatomic molecules of concern. Let us stress that each of these sets embodies diatomic molecules made of heavy metal atoms belonging to the given column of the Periodic Table; thus, bearing alike electronic configurations. We further brought together 5 more families made of heavy metal hydrides, oxides, chlorides, and alkalines. We were motivated to undertake the present research in the light of our insight with regards to (i) the general non-opacity character of neutral bodies vis-à-vis electrical field transmission, and thence (ii) the attractional electric property of neutral bodies – which underlines the disclosed constancy where, particularly for diatomic molecules comprising heavy atoms, the increase in DxR happens to get aligned with the increase in atomic weight 1 (A1) × atomic weight 2 (A2). [ABSTRACT FROM AUTHOR]

Low-levels of Nb-doped (≤2 at.%) NBT ceramics were synthesized using a conventional ceramic technique. The XRD analysis indicated the formation of a perovskite structure with rhombohedral symmetry where Nb-doping tends to expand the lattice. The dielectric characteristics and piezoelectric coupling are enhanced as a result of microdefect dipole and ferroelectric order disturbance. It was shown that E-poling influences the properties under investigation. This includes a decrease of electric permittivity (ϵ) and an increase of depolarization temperature Td and temperature Tm at which ϵ is the maximum. This is accompanied by the increase of tetragonal regions at the cost of rhombohedral phase (visible in the Raman spectra) and redistribution of the microdefect dipoles, hence ferroelectric order. [ABSTRACT FROM AUTHOR]

Lead free solid solution Bi0.5(Na0.68K0.22Li0.10)0.5TiO3-xmol%Bi2FeCrO6 (BNKLT-xBFCO), with x = 0, 0.004, 0.007, 0.013 and 0.019, ceramics were calcined at 750 °C and sintered at 1150 °C for 2 h using the solid state combustion technique. The effect of the x content on the phase formation, microstructure, electric and magnetic properties of the produced ceramics were investigated. All samples exhibited a pure perovskite phase with the co-existence of rhombohedral and tetragonal phases. The doping of BFCO enhanced the density and dielectric properties of the BNKLT ceramics. The BNKLT-0.013BFCO ceramics showed the highest density (5.87 g/cm3), excellent dielectric properties (εR∼1390, tan δR∼0.039, εm ∼4986 and tan δm∼0.075) and the highest piezoelectric constant (d33∼194 pC/N). The sample with x = 0 showed diamagnetic behavior, while the samples with 0.004-0.019 content exhibited paramagnetic behavior with higher magnetization at higher x content. [ABSTRACT FROM AUTHOR]

Solid state technique is employed to prepare La doped BNT-BFO perovskite ceramics. The sample has cubic structure and lattice strain = 0.00127 calculated by Williamson–Hall method. The frequency bands corresponding to Bi-O, Ti-O, O-, NaO, LaO and FeO stretching confirm that Fe+2, La+2 ions completely incorporate the Ti+4 ions in the B site of the perovskite. The SEM micrograph shows distinct grains and well defined grain boundaries. The dielectric study reveals grains play dominant role compare to grain boundaries. The Nyquist plots were modeled with designed circuit (CQR)(CR) and confirm that sample has semiconducting nature and supported by Cole–Cole plots. [ABSTRACT FROM AUTHOR]

The Mn-substituted NBT ceramics were prepared by the conventional ceramic fabrication technique. X-ray diffraction (XRD) studies indicated the formation of perovskite phase with rhombohedral symmetry and with small amount of second phase. It was found that 0.5mol% and 0.1mol% dopant concentration enhances piezoelectric coefficients of d33 and k33, increases the depolarization temperature Td and decreases the dielectric loss. Dielectric study showed the existence of a diffuse phase transition at Tm ≈ 320°C. It was shown that a prior electric field poling process changes the character of ϵ(T) and tanδ(T) functions, as well as shifts of Td and Tm to higher temperature. The effects are mainly caused by the reinforcement of polarization/domain ordering and by the change of content rhombohedral/tetragonal phases by electric field action. The results were discussed in terms of lattice distortion and change of defect concentration. [ABSTRACT FROM AUTHOR]

The current stage of power system development is characterised by the transformation from local electric power systems to global interconnections. It provides economic benefits, improves the reliability of power system operation and increases the quality level. However, such large interconnected systems have some technical and economical limitations, for instance, long distance transmission, and almost have a weak tie between the electric power systems. One of the main problems of the reliability of such large interconnected systems is low-frequency oscillations, which significantly reduces network capacity and leads to dynamic instability. Therefore, the analysis of the influence of various topologies and regime modes of electric power system to the low-frequency oscillations for the development of control actions and recommendations for their effective damping and reduction is relevant. In this paper, simulation and analysis was done by using of two-area electric power systems and using «EUROSTAG» software. The factors, such as the previous steady-state condition and the structure of the electric power system, affecting the damping properties of electric power system and the impact of the Back-to-Back High-Voltage Direct Current link based on voltage source converters to the damping of low-frequency oscillations were considered. [ABSTRACT FROM AUTHOR]

Electric field (E-field) effects on electric and optical properties of α-, β- and δ-SnSe have been investigated. Under the E-field, a tunable band gap of δ-SnSe appears, ranging from 2.23 to 1.26 eV. The band gap of β-SnSe could be mildly regulated by the E-field, just from 2.32 to 2.01 eV. For α-SnSe, the E-field has little effect on its band gap. We further find that the Sn-p and Se-p states mainly contribute to the variations of the band structures. Moreover, due to the application of the E-field, the absorption strength of α-SnSe in visible light might be enhanced. [ABSTRACT FROM AUTHOR]

In this study tungsten trioxide has been synthesised as a thermal infrared (TIR) absorbent by sol–gel method and characterised by X-ray diffraction (XRD), field emission scanning electron microscopes (FESEM) and transmission electron microscopy (TEM). XRD analysis shows that the single phase and hexagonal tungstate was prepared. The crystallite size measured by Scherer formula is in good accordance with the crystallite nano size measured by TEM. The polyaniline (PANI) was coated on WO3/MnFe2O3 nanoparticles (NPs, 50/50 wt%) via in situ polymerisation by core-shell structure WO3/MnFe2O3/PANI nanocomposite (50% wt as core). Structural and morphological characteristics of the produced nanocomposite were studied via X-ray diffraction, Fourier transformation infrared spectroscopy and scanning electron microscopy. The electric property was also performed by four probe method. The results showed that the WO3/MnFe2O3/PANI nanocomposites have good electric property. The TIR absorption of nanocomposite was investigated at 10–40 µm frequencies. The TIR images testing showed that the ability of infrared thermal imaging was increased by increasing WO3/MnFe2O3 as core and independent to increasing PANI as final shell. The test microwave absorption properties of the nanoparticles powder dispersing in PANI and thickness of 1.5 mm were investigated by using a vector network analysers in the frequency range of 8–12 GHz. A minimum reflection loss of the nanocomposite reaches -12 dB were observed at 8.8 and 11.6 GHz, respectively. [ABSTRACT FROM AUTHOR]

(K0.48Na0.48Li0.04)(Nb0.8Ta0.2)O3 (KNN-LT) ceramics were prepared by the traditional solid-state reaction method. The combined effects of Li and Ta additions resulted in a decrease in the orthorhombic-tetragonal (TO-T) and Curie temperature (Tc). The piezoelectric and electromechanical properties were found to be d33 ∼ 165 pC/N, kt ∼ 0.438, kp ∼ 0.363 at the sintering temperature 1178 ˚C. It has a wide temperature range for ferroelectric properties and energy storage density and possess a good temperature stability. [ABSTRACT FROM AUTHOR]

The sensitivity of boron nitride nanotube (BNNT) to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is investigated by M06-2X/6-31++G**. There are different locations on BNNT to close and interact with the TCDD. In this study, the thermodynamic and electric properties, quantitative structure–activity relationship (QSAR), HOMO-LUMO energy, and other parameters are calculated for all these probabilities. The results show, the BNNTs (12, 0) can be used as nano-sensors and nano-filtration to reduce and eliminate the TCDD. [ABSTRACT FROM AUTHOR]

The influence of Ag7GeS5I nanoparticles on dielectric properties of planar-oriented 6CB liquid crystal was investigated at 293 K within the frequency range from 6 to 106 Hz. The concentration of nanoparticles varied between 0 to 0.1 wt.%. The obtained results were compared with the influence of the same concentrations of Сu7GeS5I nanoparticles. It was shown that the Сu7GeS5I nanoparticles influence the conductivity of the liquid crystal significantly less than the Ag7GeS5I nanoparticles. [ABSTRACT FROM AUTHOR]

We investigate the effect of electric field on the properties of quasi-two-dimensional electron gas at the interface between ferroelectric oxide and insulating oxide in Ba0.8Sr0.2TiO3/LaMnO3 (BSTO/LMO) heterostructure. Interface conductivity measurements were performed by a four-point probe method before and after the effect of electric field on Ba0.8Sr0.2TiO3 ferroelectric film. We have shown that when a non-uniform electric field is applied to a ferroelectric film, we can turn off the state with high conductivity. Whereas under the influence of a uniform electric field on the ferroelectric film, we can turn on the interface state of high conductivity. [ABSTRACT FROM AUTHOR]

A comparative study on the dynamic mechanical and electric properties was firstly performed on Ba1-xCaxTiO3 (x = 0.1 ∼ 0.25) ceramics. A diphasic ceramic composed of ferroelectric tetragonal Ba0.8Ca0.2TiO3 and normal dielectric orthorhombic Ba0.07Ca0.93TiO3 solid solutions was obtained near the solubility limit (x = 0.23). The ferroelectric to paraelectric phase transition was clearly characterized by dynamic mechanical analysis (DMA) and dielectric spectrum, but the orthorhombic-to-tetragonal phase transformation for Ba0.9Ca0.1TiO3 was only detected by DMA. Relatively lower internal friction and higher remnant polarization near the solubility limit (x = 0.21–0.25) were found. In addition, the influence of poling and annealing on the mechanical properties of BCT ceramic was investigated. [ABSTRACT FROM AUTHOR]

This paper deals with the reconstruction of small-amplitude perturbations in the electric properties (permittivity and conductivity) of a medium from boundary measurements of the electric field at a fixed frequency. The underlying model is the three-dimensional time-harmonic Maxwell equations in the electric field. Sensitivity analysis with respect to the parameters is performed, and explicit relations between the boundary measurements and the characteristics of the perturbations are found from an appropriate integral equation and extensive numerical simulations in 3D. The resulting non-iterative algorithm allows to retrieve efficiently the centre and volume of the perturbations in various situations from the simple sphere to a realistic model of the human head. [ABSTRACT FROM AUTHOR]

A novel method for the calculation of eigenfrequencies of non-uniformly filled spherical cavity resonators is developed. The spectrum is determined through the introduction of effective "dynamic" potentials which encode the infill inhomogeneity. For angularly symmetric cavity, regardless of its radial non-uniformity, the set of modes is shown to be a superposition of TE and TM oscillations which can be described in terms of a single scalar function independently of each other. The violation of polar symmetry in the infill dielectric properties, the azimuthal symmetry being preserved, suppresses all azimuthally non-uniform modes of TM oscillations. In the absence of angular symmetry of both electric and magnetic properties of the infill, only azimuthally uniform distribution of both TM and TE fields is expected to occur in the resonator. The method is quite efficient for computational complex algorithms for solving different spectral problems, including those for studying the chaotic properties of systems' spectra. [ABSTRACT FROM AUTHOR]

Among La1-xCaxFeO3-δ (0 ≤ x ≤ 0.5) compounds, the optimal value of the direct current conductivity was registered for a 20% substituted amount. We therefore attempted to study the impedance and dielectric properties of 20% calcium-substituted lanthanum ferrite. We investigated the electric properties in depth between 5 Hz and 13 MHz from 350 to 800°C. The results reveal interesting properties. Indeed, the perovskite shows a huge dielectric constant which promotes its utilization in high-performance dielectric material applications. At a given temperature, ε' and tan(δ) decrease with increases in frequency. This trend was explained based on the Maxwell Wagner polarization model. The variations in dielectric loss (ε") with frequency obey the Giuntini theory based on the hopping model. As the temperature increases from 350 to 800°C, the binding energy increases from 0.22 to 0.34 eV, while the minimum hopping distance decreases from 2.16 to 0.12 pm. Consideration of the electric modulus analyzes showed that the relaxation mechanism is dominated at below 400°C by a short-range movement of charge carriers, whereas at above that temperature, a long-range movement of charge carriers is dominant. This study presents a solid foundation for the polarization and dielectric properties of lanthanum ferrite, which is a lead-free, environmentally friendly material and a promising candidate for use in nonlinear optical applications and microwave devices. [ABSTRACT FROM AUTHOR]

In some industrial devices, the use of a sliding contact to transmit power currents or communications signals is required. The physical and, in particular, tribological understanding of these electromechanical systems is therefore a major issue. Thus, this article reports a theoretical and numerical study accounting for the mechanical influences about the electric transport properties of a sliding metallic dry contact and their variations with sliding speed and contact load. These variations are characterized by analyzing the voltage noise across the contact during sliding. Results are compared to experimental data and show good agreement between theory and experiments below a critical speed value. This study is part of research and development on tribology and dynamical interface monitoring. [ABSTRACT FROM AUTHOR]

Zn-Co ferrites doped with Er3+ and Pr3+ with different concentrations were synthesised by co-precipitation method at constant calcination temperature. XRD results show an increase in the lattice parameter. Particle sizes determined from TEM are close to those determined from XRD, confirming PVP acts as controlling of the nanoparticles growth. Electron paramagnetic resonance (EPR) spectra analysis indicates that the spin-spin relaxation time T2 increases and the g-factor decreases with increasing Er3+ and Pr3+ content. The saturation magnetisation and the coercivity decrease with increasing RE3+ content. The dielectric constants ε' and ε" and the dielectric loss tangent (tanδ) decrease, and the a.c. conductivity increases with the increase of Er3+ concentration between 0.00 wt% and 0.20 wt%; the same trend is observed for samples doped with Pr3+ of concentrations 0.04, 0.12 and 0.20 wt%, while that doped with 0.08 wt% of Pr3+ shows a peak at low frequency. [ABSTRACT FROM AUTHOR]

Lead-free BiFeO3 ceramics doped with varying amounts of Bi2O3–B2O3–ZnO (BBZ) glass, that is, x wt% (x = 0.0, 0.5, 1.0, 1.5, and 2.0) were prepared via the traditional solid-state reaction route. The effects of BBZ glass content on the phase composition, microstructure, dielectric, and ferroelectric properties of BiFeO3 ceramics were investigated. X-ray diffraction results confirmed that BBZ glass doping increased the formation of secondary phases (Bi2Fe4O9 and Bi25FeO39). Scanning electron microscopy images showed that the samples with the addition of BBZ glass showed a heterogeneous size distribution of grains and more porosity. With the increase of the BBZ glass content, the fluctuation of Fe-ions was decreased and the bond strength of the Bi-O was increased. The samples with BBZ glass addition showed smaller dielectric constant and more saturated polarization hysteresis loops compared with pure BiFeO3. The Curie temperature (TC) decreased gradually from 825.8 °C for x = 0.0 to 637.0 °C for x = 2.0. In addition, leakage current density decreased with the addition of BBZ glass. These changes of the electric properties were related to the heterogeneous size distribution of grains, the generation of secondary phases and the increase of the concentration ratios of Fe3+ and Fe2+ in BiFeO3-xBBZ samples. [ABSTRACT FROM AUTHOR]

In this study, we examined the magnetic and electric properties of the Cu-doped Bi2-xCuxIr2O7 (x = 0,0.2,0.4,0.6). The X-ray diffraction confirmed that the Bi2-xCuxIr2O7 had a cubic structure. The electric transport properties indicate that the samples were in a metallic state when x < 0.4, and the metal-insulator transition occurred in the sample at x = 0.6. The behaviour of the resistivity in the composite material was produced by the electron-electron scattering process. The grain boundary effect played a dominant role in the conduction process. It was also found that the antiferromagnetic interactions enhanced with increasing Cu doping at first, but they weakened with further increases in Cu doping. These findings are explained based on the competition among the ferromagnetic Cu–Cu, antiferromagnetic Ir–Ir and antiferromagnetic Ir–Cu interactions. [ABSTRACT FROM AUTHOR]

In this study, we examined the magnetic and electric properties of the Cu-doped Bi2-xCuxIr2O7 (x = 0,0.2,0.4,0.6). The X-ray diffraction confirmed that the Bi2-xCuxIr2O7 had a cubic structure. The electric transport properties indicate that the samples were in a metallic state when x < 0.4, and the metal-insulator transition occurred in the sample at x = 0.6. The behaviour of the resistivity in the composite material was produced by the electron-electron scattering process. The grain boundary effect played a dominant role in the conduction process. It was also found that the antiferromagnetic interactions enhanced with increasing Cu doping at first, but they weakened with further increases in Cu doping. These findings are explained based on the competition among the ferromagnetic Cu–Cu, antiferromagnetic Ir–Ir and antiferromagnetic Ir–Cu interactions. [ABSTRACT FROM AUTHOR]

A novel relaxor solid solution of (1-x)Pb(Mg1/3Nb2/3)O3-xPb(Cd1/3Nb2/3)O3 [(1-x)PMN-xPCN] is synthesized by the solid-state reaction method. The crystal structure, electric properties and relaxor behavior are investigated. This system exhibits an average cubic perovskite structure at room temperature. The cation ordering, which is hardly detectable in the canonical PMN by laboratory-based high-resolution X-ray diffraction, is clearly evidenced in this solid solution. The relaxor behavior of the solid solution is found to be enhanced in the (1-x)PMN-xPCN solid solution compared with PMN. The enhanced relaxor behavior is attributed to be formation of complex ordered and disordered structures, which leads to a broader distribution of the size and dynamics of local polar heterogeneities. [ABSTRACT FROM AUTHOR]

A novel relaxor solid solution of (1-x)Pb(Mg1/3Nb2/3)O3-xPb(Cd1/3Nb2/3)O3 [(1-x)PMN-xPCN] is synthesized by the solid-state reaction method. The crystal structure, electric properties and relaxor behavior are investigated. This system exhibits an average cubic perovskite structure at room temperature. The cation ordering, which is hardly detectable in the canonical PMN by laboratory-based high-resolution X-ray diffraction, is clearly evidenced in this solid solution. The relaxor behavior of the solid solution is found to be enhanced in the (1-x)PMN-xPCN solid solution compared with PMN. The enhanced relaxor behavior is attributed to be formation of complex ordered and disordered structures, which leads to a broader distribution of the size and dynamics of local polar heterogeneities. [ABSTRACT FROM AUTHOR]

Na0.5Bi0.5TiO3 (NBT) and CoFe2O4 (CFO) powders have been prepared by sol-gel and metallo – organic (MOD) chemical solution methods respectively. The lead-free 50NBT-50CFO multiferroic particulate composite has been prepared by mixing NBT and CFO powders in required stoichiometric concentration. The structural and microstructural properties of ferroelectric (NBT) and ferrite (CFO) phases have been studied by X-ray diffraction and field emission scanning electron microscopy micrographs. The M-H curve of 50NBT-50CFO confirms the ferromagnetic behavior of the composite. The ferroelectric properties are also investigated by measuring polarization vs. electric field (P-E) hysteresis loops. Electrical properties are also studied by Keithley 2611 Source Meter. [ABSTRACT FROM AUTHOR]

Lead free Ba0.7Ca0.3O3 (BCT) ceramic has been synthesized by sol-gel method. Properties of ceramics are studied at sintering temperatures of 850 °C and 1050 °C. Structural Confirmation done using X-ray diffraction (XRD), diffractions patterns confirm the perovskite kind of structure without any impurity phase even at sintering of 850 °C. Surface morphology is studied using Scanning Electron Micrograph (SEM). Reduction in porosity and improvement in density detected at annealing temperature of 1050 °C. Improvement has been observed in dielectric constant and reduction in dielectric losses. Further ferroelectric property and leakage current density are studied under dielectric and electric study. [ABSTRACT FROM AUTHOR]