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The spark-plasma sintering of ceramics based on the cubic pyrochlore phase in the system Bi2O3-ZnO-Nb2O5 is reported for the first time. It is shown that the use of spark-plasma sintering in the manufacture of (Bi1.5Zn0.5)2(Zn0.5Nb1.5)2O7 ceramics makes it possible to obtain a high density, a homogeneous microstructure, and high dielectric parameters (almost 30% higher compared to conventional ceramic technology). The paper discusses the features of microstructure formation and the optimization of spark plasma sintering regimes. [ABSTRACT FROM AUTHOR]

This paper shows the results of experimental studies of the influence of oxygen pressure under pulsed laser deposition on the electrophysical parameters of BaTiO3 nanocrystalline films. The elemental composition of BaTiO3 films obtained at different pressures (1×10−5 Torr (vacuum) and 1×10−2 Torr (oxygen)) was studied by XPS methods. Based on the obtained results, the energy-efficient memristor structures based on BaTiO3 nanocrystalline films were proposed. It was found that 20-nm-thick BaTiO3 films based memristive structure exhibited stable resistive switching effect: HRL/LRS∼10 for 100000 cycles. The results obtained can be used to fabricate energy-efficient memristive structures. [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HAP) structures with cationic substitutions are studied. Paper presents results obtained using DFT calculations for Mg/Ca substitutions in HAP depending on Mg concentration. Data obtained showed agreement with the experiment: the lattice parameters decreased with increase in Mg concentration. A symmetry violation was found upon the Mg/Ca substitution in the Ca2 position compared to the Ca1 position, due to OH distortion and the Mg-O pair shift relative to OH channel axis. The change in piezoelectric coefficients upon these Mg/Ca2 substitutions was higher by a factor of 1.5 than those of Mg/Ca1. The corresponding changes was in the IR spectrum. [ABSTRACT FROM AUTHOR]

At present, coal mine tunneling technology is developing in the direction of intelligence and unmanned. The piezoelectric vibration energy harvester can convert the vibration energy generated by the cutting part of roadheader into electrical energy and realize the energy self-sufficiency of the low-power wireless sensor. In practical applications, the vibration frequency of the cutting part of roadheader is different, and the working condition is complex, resulting in the energy recovery efficiency of the vibration energy harvester is not ideal. In order to improve its adaptability and reliability, a separated excitation broadband piezoelectric vibration energy harvester is proposed in this paper. [ABSTRACT FROM AUTHOR]

To find out the effect of the rare earth doping element Holmium (Ho) on CuInS2 thin films, various studies have been carried out and the results have been reported in this paper. The PL study shows that intensity of doped film is more than undoped film. The PL emission peak appears at 570–580 nm. SEM images of CIS:Ho (4 ml) film shows agglomeration on the surface. Both synthesized film of CuInS2 appears to be amorphous in nature with chalcopyrite structure as clear from XRD. Hall measurement and optical studies were also performed. [ABSTRACT FROM AUTHOR]

In this paper, a composite excitation method is used to optimize the design of an existing cantilevered cylindrical ultrasonic motor to avoid vibration interference. Modal and transient simulation analysis of the stator structure was carried out by the finite element method. Optimized stator structure is simpler than the original motor. Simulation analysis results show that the circumferential amplitude is increased by more than 35% with 55.7% reduction in ceramic usage. [ABSTRACT FROM AUTHOR]

To find out the effect of the rare earth doping element Holmium (Ho) on CuInS2 thin films, various studies have been carried out and the results have been reported in this paper. The PL study shows that intensity of doped film is more than undoped film. The PL emission peak appears at 570–580 nm. SEM images of CIS:Ho (4 ml) film shows agglomeration on the surface. Both synthesized film of CuInS2 appears to be amorphous in nature with chalcopyrite structure as clear from XRD. Hall measurement and optical studies were also performed. [ABSTRACT FROM AUTHOR]

In this paper, detailed studies of effect of small amount of manganese substitution (at the zirconium site) on the structural, micro-structural, and electrical characteristics of lead zirconate titanate of Pb(Zr0.35–xMnxTi0.65)O3;x = 0, 0.02, 0.06, 0.10 (PZMT)) have been reported. The materials were prepared by using standard ceramic technology. The formation of the compounds and their basic crystal data have been studied through X-ray diffraction (XRD) method. The crystallite size and lattice strain of the compounds, evaluated from Scherrer's and Hall Williamson (H-W) equations, is found to be in the range of 40–50 nm and 11 × 10−4 to 50 × 10−4, respectively. Microstructures of different magnifications, revealing the surface nature of the compounds, have been recorded by field emission scanning electron microscope (FESEM). Effect of Mn+4 ions on electrical behavior (electrical impedance (Z*), electrical modulus (M*), conduction and relaxation phenomenon) of PZMT systems, over wide range of temperature and frequency, has been studied. [ABSTRACT FROM AUTHOR]

Rare earth yttrium substituted lithium ferrites Li0.5Zn0.1Ti0.1YxFe2.3–xO4 with nominal composition x = 0.00 to 0.10 in steps of 0.02 was prepared by the conventional ceramic method. The samples were sintered at 1050 °C for 6 h using resistive conventional heating. X-ray diffraction (XRD) patterns confirmed the formation of a single phase with a spinel structure. FTIR studies also confirmed the tetrahedral and octahedral metal-oxygen bonding of the spinel structure. Structural parameters like density, lattice constant, and crystallite size, site distances, bond length distances were measured from XRD data. The crystallite size reduces while the density increased with the progressive substitution of Y3+ ions. The Fe3+ ions at the A and the B sites mainly contributes to the electromagnetic properties of ferrites. Y3+ ions preferably entering the B sites can significantly interfere with the conduction mechanism of lithium ferrites. The objective of the present work is to find out the effect of Y3+ substitution on the structural and electrical conduction response Li-Zn-Ti ferrites. The DC resistivity initially is found to increase for concentration x = 0.04 and then decrease with further substitution. The study of the temperature dependence of DC resistivity depicts two types of conduction mechanisms in the range studied. The results obtained are analyzed and presented in the paper. [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]

Through a typical solid-state reaction followed by planetary ball milling, ABO3 structured perovskite Bi0.5Na0.5ZrO3 (BNZ) was employed as an additive to create the lead-free piezoceramic composite having compositional formula K0.47Na0.47Li0.06NbO3+(x)Bi0.5Na0.5ZrO3 where x = 0.0 wt% to 0.5 wt%. The prepared composites were characterized with the help of XRD, SEM, and FTIR. The XRD results indicated manifestation of morphotropic phase boundary (MPB), i.e. orthorhombic-tetragonal (O-T) phase boundary, for 0.4 wt% and 0.5 wt%. The SEM pictures revealed the microstructural properties of grain-grain size distribution and the average grain size of the composites. The elemental composition examination using EDAX revealed no foreign element contamination. The FTIR examination verified the development of perovskite, indicating that the BNZ has correctly fused into the KNLN matrix. The DC resistivity (ρdc) behavior was determined from IV and IR curves measured at room temperature together with varied temperature line up from 30 °C to 150 °C and a high dc resistivity ρdc of order ≈ 109 Ω cm was obtained for all the ceramics. The results have been analyzed and the mechanism pertaining to the results has been discussed in the paper. Thus the main idea was to develop a lead-free piezoceramic composite by incorporating Bi0.5Na0.5ZrO3 as an additive and investigating its effect on the above mentioned properties of the composite material. [ABSTRACT FROM AUTHOR]

To find out the effect of the rare earth doping element Holmium (Ho) on CuInS2 thin films, various studies have been carried out and the results have been reported in this paper. The PL study shows that intensity of doped film is more than undoped film. The PL emission peak appears at 570–580 nm. SEM images of CIS:Ho (4 ml) film shows agglomeration on the surface. Both synthesized film of CuInS2 appears to be amorphous in nature with chalcopyrite structure as clear from XRD. Hall measurement and optical studies were also performed. [ABSTRACT FROM AUTHOR]

To find out the effect of the rare earth doping element Holmium (Ho) on CuInS2 thin films, various studies have been carried out and the results have been reported in this paper. The PL study shows that intensity of doped film is more than undoped film. The PL emission peak appears at 570–580 nm. SEM images of CIS:Ho (4 ml) film shows agglomeration on the surface. Both synthesized film of CuInS2 appears to be amorphous in nature with chalcopyrite structure as clear from XRD. Hall measurement and optical studies were also performed. [ABSTRACT FROM AUTHOR]

Professor Boris Anatol'evich Strukov, a renowned scientist in the field of ferroelectrics, passed away at the age of 88 in Munich, Germany. He had a distinguished career at Moscow State University, where he made significant contributions to the study of phase transitions in ferroelectric crystals. Professor Strukov was known for his meticulous approach to experimental research and his dedication to understanding the underlying theories. His work challenged existing theories and provided valuable insights into the behavior of ferroelectric materials. He also co-authored a popular textbook on ferroelectricity and continued to engage in conceptual discussions even after retiring from teaching. Professor Strukov's legacy includes his numerous publications and his passion for scientific curiosity. [Extracted from the article]

Temperature dependences of Brillouin light scattering spectra from Ba0.5Sr0.5 Nb2O6 (SBN 50) film were obtained. The deviations of the Brillouin shift dependence from linear near ferroelectric phase transition are due to electric fields in the local regions with symmetry breaking. A maximum of Brillouin line width is more than twice of the corresponding width in a bulk crystal of the same composition. This broadening is attributed to the confinement of the acoustic phonons. Optical second harmonic generation measurements (SHG) showed that the transition from the polar to the nonpolar phase occurred at a temperature characteristic of SBN-50. [ABSTRACT FROM AUTHOR]

The evolution of as-grown domain structure under the action of the series of rectangular electric field pulses at the elevated temperature was studied by in situ optical imaging in calcium orthovanadate single crystals. It was revealed that the domain switching was accompanied by formation of the holes in the electrodes stimulated by conical domains reaching the surface. The multistage scenario of the domain kinetics was considered. It was shown that the evolution of the domain structure represented the independent growth of few large domains by motion of the smooth domain walls in the bulk and at the surface. [ABSTRACT FROM AUTHOR]

The formation of submicron stripe domain structures was studied during two-stage switching with a change in the dimensionality of domain growth in congruent lithium niobate with a dielectric layer on the polar surface at elevated temperature. At the first stage, a two-dimensional hexagonal microdomain lattice representing a structure of isolated domains was created using the photoresist mask. After that, the polar surface was covered by solid dielectric layer. Thus, switching at the second stage was carried out under inefficient screening of depolarization field leading to growth of the stripe domains only. Self-organized formation of domain stars and snowflakes was demonstrated. [ABSTRACT FROM AUTHOR]

In the present study, particular aspects of the large-signal switching properties and electromechanical hysteresis of the lead zirconate titanate (PZT)-type porous piezoceramics were studied in comparison with the dense piezoceramics of the same composition. Large-signal ferroelectric polarization and strain hysteresis loops were recorded at the bipolar electric fields in the range of 0 ÷ 5 kV/mm and in the frequency range of 0.01 ÷ 5 Hz. Measurements and analysis were performed by means of the electromechanical measurement system (STEPHV) and electromechanical response characterization program (STEP), combining large-signal modeling of the mechanical and electrical behavior of ferroelectric materials. [ABSTRACT FROM AUTHOR]

In this work, the piezoelectric hysteresis and relaxation process induced by a weak DC electric field in ferroelectric ceramics were studied using the impedance spectroscopy method and piezoelectric resonance analysis program (PRAP). The DC field and time dependences of the complex dielectric constants were measured for the radial extensional mode of vibrations of thin piezoceramic disks. It was found that the hysteresis and relaxation nature of the field and time dependences of the complex dielectric constants were caused by the reversible displacements of 90° domain walls as well as the space charge transformation. [ABSTRACT FROM AUTHOR]

The article presents computer modeling and quantum-chemical calculations of polar and photoelectronic properties of helix-like nanotubes based on dileucine (LL) and diisoleucine (II) dipeptides of L and D chiralities using HyperChem package. It has been shown that physical properties of LL-based peptide nanotubes (PNTs) are close to the properties of diphenylalanine (FF) nanotubes, whereas II-based PNTs demonstrate lower polarization and the absorption edge in the short-wavelength UV-C region. For all kinds of nanotubes, the chirality index calculated using scalar triple product of dipole moments has confirmed the chirality change rule established earlier for complex biomolecules. [ABSTRACT FROM AUTHOR]

Triboelectric generation during the friction of the boron doped diamond probe on the p-doped silicon surface with a native oxide layer was studied. Triboelectric generation was detected at the probe loading force higher than 1 µN leading to the modification of the studied surface. Triboelectric current density reached value of 4·104 A/m2. Removal of the native oxide layer confirmed the tribo-tunneling mechanism of the electric current generation. Increase in the triboelectric current by the high loading force was explained by the increase in the contact area and the generation of the dangling bonds during the friction. [ABSTRACT FROM AUTHOR]

The features of the response of frustrated states to the external field are considered on the example of a diluted Ising chain. In the ferromagnetic case, partial ordering occurs, which leads to a decrease in entropy. In the antiferromagnetic case, the switching on of the field leads to the appearance of a long-range order in the system, although the state remains frustrated. A mapping of a one-dimensional spin model to a Markov chain is proposed, which makes it possible to study in detail the properties of correlation functions and local distributions of the states in the spin chain. [ABSTRACT FROM AUTHOR]

We develop a unified approach to description of Jahn-Teller (JT) magnets – compounds based on JT d-ions with t2gn1egn2 type configurations in a highly symmetrical octahedral, cubic, or tetrahedral environment and ground state orbital E-doublet. Rich variety of their phase states: non-magnetic and magnetic insulators, multiferroics, strange metals and unconventional superconductors is related to the instability of their highly symmetric JT "progenitors" to charge transfer with anti-JT d-d disproportionation and formation of a system of effective local composite spin-singlet or spin-triplet S-type bosons moving in a non-magnetic or magnetic lattice. We present a short overview of physical properties for actual JT-magnets. [ABSTRACT FROM AUTHOR]

In this study, we aim to investigate theoretically the critical characteristics of spin −1/2 four-leg nanotube for the nanotechnology applications. The Ising model simulated by Monte Carlo simulation is adopted with the first exchange coupling J , the second exchange coupling between the second nearest neighbor atomic spins J ′ and the transverse exchange coupling J z , and the external magnetic field h as parameters. Herein, we examine the local properties of spin −1/2 four-leg nanotube by analyzing the magnetization, susceptibility and hysteresis loop behavior as function of J ′ , J Z and h. The obtained results show that the isotropic ‐ 1 / 2 four-leg nanotube Ising model presents critical behavior at ferromagnetic to paramagnetic phase transition where the Curie temperature T C increases according to vertical and second nearest neighbor exchange coupling. Furthermore, under external magnetic field, the magnetization keeps the second order transition and the magnetic susceptibility declines with the increase of applied external magnetic field value. In addition to that, we have found single ferromagnetic hysteresis loops, for which the shape increases by increasing the second nearest neighbor exchange coupling when T = J. Finally, the critical temperature shows perfect mirror symmetry relative to the vertical and increases with the second nearest neighbor exchange coupling. [ABSTRACT FROM AUTHOR]

In this study, an L-beam vortex-induced vibration piezoelectric energy harvester with interference step is proposed. The experimental results show that the interference step can broaden the effective wind speed bandwidth in the second resonance region of the energy harvester and increase its energy output amplitude significantly. When the load resistance is 90 kΩ, the effective wind speed bandwidth in the second resonance region of the energy harvester can be expanded by a maximum of more than 200%, and the peak output power can be increased by a maximum of 291% by adjusting the position, width and height of the step. [ABSTRACT FROM AUTHOR]

Sr(Bi3.9-xNdxLa0.1)(Ti3.975Zr0.025)O15 (x = 0.00, 0.025, 0.05, 0.075 and 0.1) ceramics were prepared by solid-state reaction technique. It was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Energy Dispersive Spectra (EDS). The impedance spectroscopy and conductivity studies were investigated. XRD analysis indicated, the formation of a single-phase orthorhombic structure and particle size was found by SEM. The compositions were confirmed from their EDS spectra. Impedance plots were used as tools to analyze the sample behavior as a function of frequency and temperature. Cole-Cole plots were showed that a non-Debye relaxation. Conductivity measurements were performed on it. [ABSTRACT FROM AUTHOR]

In the present work, the electronic structure, elastic parameters, density of states (partial and total), optical properties, and charge density of ZrB5 (B = Se, Te) have been investigated by means of first principles calculations. The generalized gradient approximation has been used for modeling the exchange-correlation effects. It has been observed that the calculated lattice parameter values are in agreement with the values in the literature. The second-order elastic constants were calculated, and the other related quantities have also been estimated. The electronic band structures and the partial density of states corresponding to these band structures of ZrSe5 and ZrTe5 are examined, and it is understood that ZrTe5 and ZrSe5 are narrow band semiconductors or semimetals. Finally, the electron energy loss function (ELS) spectra and charge density of ZrB5 are calculated and interpreted. [ABSTRACT FROM AUTHOR]

The study of Weyl points in electronic systems has recently inspired extensive research in classical systems, such as photonic and acoustic lattices. We construct a single-phase three-dimensional structure, an analog of the honeycomb lattice, and then predict the existence of Weyl points with opposite topological charges (±1) as well as the associated gapless topologically protected surface states. We apply full-scale numerical simulations on the elastic three-dimensional structure and present a clear visualization of the topological surface states that are directional and robust. Such designed lattices can pave the way for novel vibration control and energy harvesting on structures that are ubiquitous in many engineering applications. [ABSTRACT FROM AUTHOR]

Using DFT-based molecular dynamics simulation of Cu+ cations flipping and In3+ cations displacive dynamics, we clarify the dipole ordering of CuInP2S6 ferrielectrics through the second order Jahn-Teller effect which determines the double-well potential for copper cations as well as three-well potential for indium cations inside the structural layers. The temperature dependence of the spatial distribution of Cu+ and In3+ cations is also described within the quantum anharmonic oscillator model. In3+ cations play a decisive role in the character of the polar ordering: at ambient or for positive pressures, the first order transition occurs; with the rise of negative compression, the ferrielectric transition evolves to the second order. The peculiarities of spontaneous polarization switching are related to the contributions of copper and indium cationic sublattices. [ABSTRACT FROM AUTHOR]

The wide band gap of complex oxides is one of the critical challenges restricting their usage in photovoltaic cells. Therefore, examinations of their photoelectric characteristics have increasingly concentrated on materials with a low band gap. This work investigated the effects of iron doping on samarium-modified Bi4Ti3O12-based oxides (BSmT) made via a solid reaction approach to control the band gap of complex oxides. X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-Vis), and X-ray photoelectron spectroscopy (XPS) were used to study the synthesized materials' structural, optical, and oxygen vacancies. Doping with Fe atoms significantly increased the tunability of the band gap from 3.20 eV to 1.81 eV without violating symmetry. The tuning of bandgap energy in this system was explained based on structural distortion and the formation of oxygen vacancies. This work examined the ferromagnetism and ferroelectricity ordering of the sintered BSmT:F0% and BSmT:F10% samples at room temperature to demonstrate the multiferroelectricity behavior. The findings indicate unsaturated P-E hysteresis loops driven by domain pinning caused by oxygen vacancy formation near domain boundaries. Simultaneously, significant S-type M-H hysteresis loops showed weak ferromagnetic ordering. The findings in this study are encouraging for the development of intrinsic multiferroics for photovoltaic devices for future applications. [ABSTRACT FROM AUTHOR]

One of the negative effects of ferroelectric applications, particularly for electrocaloric effect (ECE) applications, is temperature hysteresis (ΔTHyst). Temperature hysteresis is the difference between the temperatures corresponding to the maximum dielectric permittivity in heating and cooling modes. The value of ΔTHyst is commensurate with the value of the ECE temperature change. The ECE is a phenomenon in which a material shows a reversible temperature change under an applied electric field. The aim of this work is to study the possibilities of temperature hysteresis reduction by varying the ceramic sintering temperature, changing the stoichiometry of BaxSr1-xTiO3 solid solutions, and changing the rate of the heating-cooling cycle. [ABSTRACT FROM AUTHOR]

The circuit simplification and simple structure of piezoelectric motor have become a major trend at present. Therefore, a novel, miniaturized, single-phase driven piezoelectric motor is proposed. The suggested piezoelectric motor employs a bending vibration mode of the first order, which is inspired by the motion patterns of fish tail fins. First, the motor's operational principle and structure are explained. By analyzing the relationship between the working frequency and amplitude of the motor and the output power, the key parameters of the motor are determined, and the structure size of the motor is calculated. Next, the FEM model of the stator is utilized to conduct transient analysis in order to examine the movement path of the driving foot. Symmetrical right-diagonal or left-diagonal motions are formed by the driving foot during the first bending vibration, creating oblique elliptical movements. Finally, a prototype is made and its vibration and mechanical characteristics are tested. At a frequency of 15.6 kHz, the motor's highest speed without any load is measured at 31.2 mm/s. Both forward and backward performance is identical. When the motor is supplied with a voltage of 140 Vpp and a preload of 2 N, it achieves a moving speed of 4.2 mm/s at 15.6 kHz, with an output thrust of around 0.9 N. [ABSTRACT FROM AUTHOR]

BiFeO3 nano-ceramics were synthesized using the low-temperature molten salt synthesis route to study the influence of calcination temperature and salt ratios. The Rietveld refinement revealed the distorted perovskite structure of BFO. These granular-shaped BFO samples' grains morphology was studied using the FESEM. The FTIR revealed the presence of Metal-Oxygen bonds in the BFO ceramics. The XPS studies exhibited the respective constituent elements' oxidation states and validated the presence of oxygen ion vacancies. The frequency-dependent dielectric properties were measured at various temperatures. The electrical conductivity measurement showed a linear variation as a function of frequency which validated Jonscher's power law. [ABSTRACT FROM AUTHOR]

The performance of the 0–3 piezoelectric composite consisting of two piezoelectric materials (PZT5H and PVDF) is analyzed to improve the piezoelectric properties for sensing applications using FEA and validated with the experimental and analytical results. The experimental and predicted results are showing good matches. The average piezoelectric coefficient d33 of the piezoelectric composite and the effective elastic, dielectric and piezoelectric properties of the 0–3 passive matrix piezoelectric composite were determined from the unit cell model. It is observed from the analysis that the performance of 0–3 piezo-composite has excellent piezoelectric properties and also optimized unit cell size and polymer matrix. [ABSTRACT FROM AUTHOR]

The microwave dielectric properties of La2MoO6 ceramics were investigated in preparation for their application in mobile communication. La2MoO6 ceramics were prepared by the conventional solid-state method under varied sintering conditions. The X-ray diffraction peaks of La2MoO6 ceramic did not vary significantly with sintering conditions. The average grain size of La2MoO6 ceramics increased with increasing the sintering temperature and duration. The maximum density of 5.67 g/cm3, the dielectric constant ( ε r ) of 14.1, the quality factor (Q × f) of 68,000 GHz, and the temperature coefficient of resonant frequency ( τ f ) of −56 ppm/°C had been attained when La2MoO6 ceramics that sintered at 1300 °C for 4h. [ABSTRACT FROM AUTHOR]

This work aims to study the electrical and optical properties of CuInS2 thin films to see the impact of rare earth doping on the properties of films obtained by Chemical bath deposition (CBD) in alkaline medium at 80 °C bath temperature. The observed and calculated lattice parameters are in good agreement with each other as confirmed from structural studies. Hall mobility and other parameters were calculated. The mobility of Pr doped film was quite high. E = hν = hc λ has been used to calculate the band gaps of various doped films of CuInS2. It is found that band gap is low for Sm doped film. This could be due to small particle size. Presence of dopant has been confirmed from EDS. PC studies has been done to know about the possible states in band gap. The photoconductive gain is high in Sm doped film. The emission spectrum were recorded for the wavelength 300–1000nm. The peak sharpness in terms of intensity is very high in Sm doped films. Spherical shape particles are prominently appeared on the surface of the film. [ABSTRACT FROM AUTHOR]

The present work describes the effect of deposition temperatures and pH values on structural, morphological, and electrochemical properties of cuprous oxide (Cu2O) thin films deposited on the conductive SnO2 glass substrates by using electrodeposition technique in an acidic system. The chronoamperometry curve of the solution was tested on an electrochemical workstation. X-ray diffraction patterns indicate that the deposited films have better crystallinity which is deposited at the deposition temperature of 50 °C and pH value of 5–6. Scanning electron microscopy displays that surface morphology of the deposited films varied greatly with the deposition temperature and pH value rising. The results of quantitative study of the target product films by Energy Dispersive Spectrometer (EDS) show that they are all in line with the element content ratio of Cu2O. By measuring the resistivity and conductivity of the deposited films, it was found to be in the semiconductor range. [ABSTRACT FROM AUTHOR]

This study investigates the dielectric properties, including dielectric constant (ɛ′), dielectric loss (ɛ″), tangent delta (tan δ), and AC conductivity (σac), of PVA/Y2O3 polymer nanocomposites (PNCs). The dielectric behavior of the PNCs was examined as a function of frequency and temperature. The results revealed that the addition of Y2O3 nanoparticles to the PVA matrix influenced the dielectric properties of the composites. In contrast to pure PVA, the PVA/Y2O3 PNCs with a 15 wt% Y2O3 loading exhibited high values of ɛ′, ɛ″, tan δ and σac are 647.49, 1607.48, 9.70 and 1.024 × 10−5, respectively, at low frequency and at particular temperature. Furthermore, the electrical properties of PVA/Y2O3 PNCs were also investigated using the Cole-Cole plots. These plots provide valuable insights into the complex impedance behavior and allow for comprehensive understanding of the electrical response of the nanocomposites. [ABSTRACT FROM AUTHOR]

This communication presents the effect of Yttrium and Strontium doping on structural and electrocaloric characteristics of Bismuth Sodium Titanate. Bi0.25Na0.35Sr0.3Y0.1TiO3 electroceramics was synthesized by traditional solid-state mixed-oxide technique. The crystallographic phase formation was confirmed using the X-ray diffraction technique. Rietveld refinement was carried out to extract the unit cell parameters. Average particle size was estimated from the full-width half maxima of the strong XRD peak using Debye-Scherrer's equation. The temperature dependence of the maximum polarization obtained from P-E loops, the electrocaloric ability of the BNSYT is estimated by calculating the change in the entropy at a field of 6 kV/cm using the standard thermodynamics relation. [ABSTRACT FROM AUTHOR]

The present work centered attention on novel ionic liquid (IL) based on dicationic benzimidazolium ion containing amide group (DBimIL) synthesized using dialkylation of N-ethyl benzimidazole to followed with anion exchange reaction. To explore the potential application of ILs, there is a great need to grasp their structural and physical properties. We have developed three different set of DBimIL based ionic liquids with chloride, hexafluorophosphate and perchlorate anions in aqueous media, respectively. Their structural features were studied using 1H, 13C-NMR, FTIR, and HRMS spectroscopy, respectively. The temperature-dependent dielectric characteristics of ILs were closely examined angular frequency in the range of 0.6–125 rad/s from 30 to 150 °C. The relationship between the structural and dielectric properties of ILs established. The dielectric parameters like dielectric constant, dissipation factor and the real part of ac conductivity were found to be affected significantly with the tuning of anionic moieties of ionic liquids. The ability of materials to store a charge in electromagnetic field was measured. From dielectric and electrical studies, to bring to an end, especially in particular way that the present IL systems have an enormous potential for the designing of modern-day energy storage devices. [ABSTRACT FROM AUTHOR]

We report the preparation and characterization of vanadium substituted four-layer Aurivillius compound Bi5Fe1.5V0.5Ti2O15 using spin coating method. Ferroelectricity in the prepared films are confirmed from the well saturated polarization vs electric field (P-E) loops having remnant polarization (2 Pr) around 12.94 µC/cm2 at room temperature. In addition, low temperature P-E measurements show a decrease in Pmax and 2 Pr, which is attributed to the stabilization of defect dipole complexes and domain pinning, as seen in bismuth-based ferroelectrics. Additionally, this decrease in polarization is accompanied by an increase in imprint, confirming the presence of defect dipoles manifested as internal fields. [ABSTRACT FROM AUTHOR]

Cobalt disulfide (CoS2) is a highly sophisticated metal chalcogenide that has garnered significant attention due to its distinctive properties such as its electrical, optical, catalytic, and magnetic capabilities and potential for use in a range of applications. In this work, pure CoS2 nanoparticles were synthesized using the economical and facile hydrothermal method. The X-Ray diffraction (XRD) method was used to characterize the synthesized sample, confirming that it has a cubic crystal structure with space group P a −3. The Debye-Scherrer's formula was implemented to determine the average crystallite size of nanoparticles and found to be 24.24 nm. Through the use of Field Emission Scanning Electron Microscopy (FESEM), the morphology and effective grain size of the obtained sample was determined. FTIR spectrophotometry was used to examine the vibrational stretching of the various bonds in CoS2. UV-Vis spectroscopy is employed to measure the optical property of the sample. The optical bandgap calculated from the Tauc Plot is around 1.90 eV reflecting the presence of photovoltaic properties in the sample. The change in dielectric permittivity and loss have been observed for the sample in the frequency range of 100 Hz to 10KHz at different temperatures between 303K and 423K. The frequency-dependent electrical conductivity of CoS2 is also explained. The observations revealed the presence of unique electrical and structural properties in the synthesized sample. [ABSTRACT FROM AUTHOR]

Soft ferrimagnetic spinel lithium based oxides were prepared with additives like V2O5 and Na2SiO3 and sintered with the efficient microwave sintering technique. Tetravalent metal ions substituents like Mn+4, Ti+4 were used to enhance the important properties like D. C. resistivity, saturation magnetization, permeability, hysteresis and dielectric behavior. The ferrites were sintered at different sintering temperatures viz., 900, 950 and 1000 °C for 10 min by microwave technique and by conventional technique at 1050 °C for 4h. X-ray diffraction (XRD) studied the structural behavior which confirmed the spinel characteristics, Scanning electron microscopy (SEM) and EDAX revealed the microstructural and elemental compositions respectively of the ferrites. The use of additives and the microwave sintering significantly influencing the microstructural behavior and subsequently on the electromagnetic properties could be observed. Studies of initial permeability and initial permeability loss found to remain nearly constant with change in frequency until at certain frequency they showed resonance behavior. The resonance frequency's dependence on the microstructures of the ferrites could be observed. Temperature dependence behavior of the dielectric parameters and the B-H loop traced from torroidal samples of the ferrites were studied. [ABSTRACT FROM AUTHOR]

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

In this report, we are presenting the effect of B-site co-doping with Sn and Zr (2% each) on frequency and temperature-dependent dielectric and electrical properties of Ba0.5Sr0.5TiO3 (BST). The desired compound is synthesised following solid-state reaction route and the structural and micro-structural study of the resulting compound is done using X-ray diffractometer (XRD) and scanning electron microscope (SEM) technique. XRD study revealed that the parent structure of BST is mostly retained after co-doping. SEM micrograph analysis presented dense packing of grains of different sizes distributed all over the volume of compound formed. The compound was found to have a moderate value of dielectric constant and low tangent loss along with a near stable response of these dielectric properties over the studied frequency range, suggesting its possible application in tuneable matching networks and frequency agile antennas. Electrical properties study suggested a non-Debye type electrical response with a thermally activated conduction mechanism occurring in the material. The dependence of conductivity with temperature showed negative temperature coefficient of temperature behaviour of the compound and the ac conductivity spectrum followed Johnscher's power law. The variation of exponent with temperature suggested correlated barrier hopping conduction mechanism in the material. [ABSTRACT FROM AUTHOR]

There are many nanoparticle preparation techniques such as the biological approach sol-gel method and physical methods, etc. However, the co-precipitation approach requires few chemical reagents and reaction time as well as produces highly pure products with comparatively lower costs among the available techniques. In present work co-precipitation method is use to synthesize magnetic iron oxide (Fe3O4) nanoparticles, followed by characterization to check its applicability and the presence of undesired substrate. UV–visible spectroscopy, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and Fourier-Transform Infrared Spectroscopy (FTIR) were examined to determine the synthesized Fe3O4 nanoparticles. The nanoparticles' sizes lies between 1 nm to 100 nm, according to the SEM and HR-TEM analyses. XRD measurements verified the crystalline characteristics of the Fe3O4 nanoparticles. Dielectric spectroscopy of synthesized Fe3O4 nanoparticle pellets has been investigated at a wide frequency range 0.1 to 105 Hz. Capacitance and dielectric permittivity of Fe3O4 nanoparticles decrease continuously with frequency as dipole gets less time to orient in the field. The dielectric permittivity of Fe3O4 pellets increases up to 3 mm thickness and subsequently drops, perhaps because a rise in resistance. The electrical conductivity of Fe3O4 rises exponentially with frequency. According to the dielectric studies, the dielectric permittivity and electrical conductivity of Fe3O4 are greatly dependent on the thickness and extent of frequency. Additionally, the dielectric impedance of Fe3O4 pellets has also been investigated as a function of frequency. [ABSTRACT FROM AUTHOR]

Ion incorporation and polarization are useful techniques to enhance the osteo-repair properties of a potential biomaterial biphasic calcium phosphate (BCP) for bone regeneration with a controlled rate of disintegration. BCP scaffolds were dopped with zinc (Zn), which is an important trace element that supports osteogenesis as well as suppresses osteoclastogenesis. In the present study, Zn-BCP scaffolds were fabricated by wet chemical method with varying Zn concentration. The main objective of this study was to investigate the biomedical properties of Zn-BCP scaffold after negatively poling its surface. The produced scaffolds were cultured with MG63 osteoblast like cells and S. aureus bacterial cells. The in vitro results showed that the cell viability was increased after 1, 3 and 5 days of culture along with increase in the relative expression of gene markers. The combined effect of Zn-incorporation and polarization enhanced the antibacterial efficacy of the fabricated scaffolds. Based on the findings it was observed that these negatively polarized Zn-BCP scaffolds have promising application for bone tissue engineering with excellent osteogenic as well as antibacterial characteristics. [ABSTRACT FROM AUTHOR]

Using DFT-based molecular dynamics simulation of Cu+ cations flipping and In3+ cations displacive dynamics, we clarify the dipole ordering of CuInP2S6 ferrielectrics through the second order Jahn-Teller effect which determines the double-well potential for copper cations as well as three-well potential for indium cations inside the structural layers. The temperature dependence of the spatial distribution of Cu+ and In3+ cations is also described within the quantum anharmonic oscillator model. In3+ cations play a decisive role in the character of the polar ordering: at ambient or for positive pressures, the first order transition occurs; with the rise of negative compression, the ferrielectric transition evolves to the second order. The peculiarities of spontaneous polarization switching are related to the contributions of copper and indium cationic sublattices. [ABSTRACT FROM AUTHOR]

Piezoelectric energy harvesting has garnered greater interest in the past two decades than other vibration energy harvesting techniques for wireless power sensors and portable electronics. This work initially considers a bimorph cantilever with a solid substrate for analysis, keeping the first eigenfrequency below 100 Hz for environmental energy harvesting. Polyvinylidene fluoride (PVDF)-polymer is used as piezoelectric material due to its higher flexibility and brass is used as a substrate. The cantilever beam of length (L), width (B), the thickness of the substrate (ts) and piezoelectric layer (tp) are 50, 12.5, 0.14, and 0.25 mm, respectively, considered for analysis and having an eigenfrequency of 44 Hz. Further, an auxetic substrate (elliptical structure) and functionally graded piezoelectric material are incorporated to enhance power output. The maximum power is obtained as 8.33, 8.97 and 3.3 mW for conventional (solid) substrate, auxetic substrate and functionally graded piezoelectric layer under 3.5g excitation. The auxetic design has enhanced power output, whereas functionally graded materials have better surface bonding. [ABSTRACT FROM AUTHOR]