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With the waste of resources caused by human activities, it has gradually become an increasingly prominent social problem. The development of self-healing polymers in the field of insulation has attracted widespread attention. Develop polymer matrices with efficient healing efficiency and sound insulation properties to achieve green and sustainable resource conservation. In addition, improving the dielectric properties of intrinsic self-healing matrices has been a hot topic. In this work, we developed a new PEI matrix-modified self-healing polymer substrate that provides a breakdown field strength of 240 kV/mm and self-healing properties at room temperature, this has significantly improved the dielectric properties over other previously reported self-healing polymers. In addition to the abovementioned performance, we found significant differences in thermodynamic behavior in the synthesized end-modified polymers. By dielectric characterization (LCR), the breakdown composite can be left at room temperature for 60 min, and the material can recover 80 % of the initial properties without external intervention(This is demonstrated by the fact that its DC conductivity at 60 min of autonomous healing was significantly changed from that of the freshly electrically pierced DC conductivity and remained around 5.38 × 10−11 S/cm for a longer period of time thereafter). The microscopic morphology of the modified PEI matrix was observed by scanning electron microscopy (SEM) and EDS surface elemental analysis, which further supports the existence of metal coordination structures. These findings can further deepen the thinking of self-healing dielectric composites. The work inspired by this may break the limits and take self-healing composite dielectric materials to a new height. [ABSTRACT FROM AUTHOR]

High entropy oxides with interesting physical properties can be obtained by the design of A-site cations. Herein, a series of medium entropy and high entropy perovskite ceramics (Ba 0.25 Sr 0.25 Ca 0.25 Bi 0.25)TiO 3 , (Ba 0.2 Sr 0.2 Ca 0.2 Bi 0.2 La 0.2)TiO 3 , (Ba 0.2 Sr 0.2 Ca 0.2 Bi 0.2 Na 0.2)TiO 3 and (Ba 0.2 Sr 0.2 Ca 0.2 La 0.2 Na 0.2)TiO 3 were synthesized by the solid-state method, which selected various valence elements to achieve a single-phase structure and increase the lattice distortion. The microstructure indicated that the high-entropy ceramics exhibited the same macroscopic single perovskite while the local configuration is different. Mesoscopic results show that high entropy can adjust the polarization and relaxation of ferroelectrics, so as to optimize the energy storage performance. Meanwhile, the results manifest that grain boundaries, oxygen defects and relaxation can be changed by entropy configuration. Our work proves that the properties of high entropy ferroelectric materials can be regulated by different valence states of the elements in high entropy and explores the relevant mechanism, which provides a possible opportunity for the design and application of high-entropy dielectric materials with excellent properties. [ABSTRACT FROM AUTHOR]

Extensive studies on TiO 2 -based colossal permittivity (CP, dielectric constant ε' >103) materials have focused on the cation doping of metal elements; however, little attention has been paid to nonmetallic dopants. Compared to metallic elements, nonmetallic atoms with small radii and high activities, such as H, C, B, and N, can be used as anion-doping elements. Their incorporation into the TiO 2 lattice includes interstitial and substitutional doping, which can influence the bandgap of TiO 2 and its electron transport performance differently, thereby exhibiting considerable potential in TiO 2 -based applications. In this study, different N-containing compounds (BN and NH 4 Cl) were doped into rutile TiO 2 , while homogeneous ceramics of single-phase rutile TiO 2 were prepared via solid-state sintering. The effects of co-doping N, Cl, and N, B on the dielectric properties of rutile TiO 2 ceramics were investigated. While N and Cl doping showed no considerable effect on the dielectric properties of rutile TiO 2 ceramics, the co-doping of N and B doping in rutile TiO 2 considerably increased the dielectric constant to >104 with suppressed tan δ in a wide frequency range from 1 kHz to 10 MHz. These ceramics exhibited excellent frequency stability (up to 100 MHz) and temperature stability (153–513 K), which outperforms most reported transition metal co-doped TiO 2 ceramics, thereby highlighting the untapped potential of the non-metallic dopants in enhancing dielectric materials. [ABSTRACT FROM AUTHOR]

Glasses formed from transition metal oxides have shown tailorable electrical and optical properties depending on the valence state and individual element. Vanadate glasses have received specific attention for their high conductivities as compared to most glass families. In this study, the frequency‐dependent capacitance and direct current (dc) conductivity properties of alkaline earth vanadate glasses were investigated. Glasses in the xSrO–(100 − x)V2O5 and xBaO–(100 − x)V2O5 systems, where x = 30, 40, and 50 in mol%, were prepared via melt‐quench synthesis. Capacitance measurements were used to calculate dielectric constants, dielectric loss, and alternating current (ac) conductivity for each sample. Dielectric constants varied between 10–13 and 14–16 for SrO–V2O5 and BaO–V2O5 glasses, respectively, at 1 MHz. Current measurements were made as a function of temperature and voltage for each glass sample. A strong dependence on vanadate content was noted where temperature had a less strong effect. Activation energies were calculated to describe electrical transport mechanisms. All samples showed activation energies governed by electron hopping mechanisms. Such vanadate glasses have properties suitable for applications as cathode materials for batteries, solid state electrolytes, and conductive glass paste with potential for electro‐optic effects involving nonlinear processes. [ABSTRACT FROM AUTHOR]

Some physical properties (structural, dielectric and optical) of a complex lead-free ceramic [ Bi 1 ∕ 2 Na 1 ∕ 2 ][ Fe 1 ∕ 2 W 1 ∕ 2 ]O3 have been thoroughly examined in different experimental conditions in this study. It was fabricated via a solid-state reaction method. The crystal structure is monoclinic, according to the detailed analysis of the X-ray diffraction pattern. Also, the functional vibrational bands can be observed in the FT-IR and Raman spectra, which support the creation of the molecular structure. Scanning electron microscope (SEM) images of the sample clearly show the effects of Na + and W 6 + incorporation in morphology, and energy dispersive X-ray spectroscopy (EDX) indicates the existence of all constituents. The non-overlapping small polaron tunneling (NSPT) and correlated barrier hopping (CBH) model conduction mechanisms are examined through Jonscher's power law. The contribution of the grain and grain boundary to the capacitive behavior is shown by Nyquist plots. According to a leakage current analysis, the compound exhibits Ohmic and space charge limited conduction (SCLC) conduction mechanisms. Electric field polarization was used to study the ferroelectric nature. The findings of this study show that the inclusion of Na + and W 6 + is an efficient technique to improve its dielectric and optical characteristics. [ABSTRACT FROM AUTHOR]

Polymer-based dielectric composites show great potential prospects for applications in energy storage because of the specialty of simultaneously possessing the advantages of fillers and polymer matrices. However, polymer-based composites still have some urgent issues that need to be solved, such as lower breakdown field strength (Eb) than polymers, dielectric mismatch, and the poor interface between the matrix and the filler. Hence, this review provides a systematic summary of recent research advances in improving the energy storage properties of polymer-based composites from several aspects, mainly including polymer matrix types, optimization of filler shapes, surface modification of fillers, and design of multi-layer composite structures. Finally, some existing challenges and future perspectives are outlined and discussed to facilitate the further development of polymer-based composites in the energy storage field. We believe this review will help researchers better understand the current development status of polymer-based composites in the energy storage field, and push it forward to a new research stage. [ABSTRACT FROM AUTHOR]

The influence of density and shape of hollow silicas (silica hollow tubes (SHT) or hollow glass microspheres (HGM)) on dielectric and heat‐resisting characteristics of poly(ether ketone ketone) (PEKK)/SHT and PEKK/HGM films was systematically investigated. The dielectric characteristics of PEKK/SHT or PEKK/HGM films decrease to a minimum, as their SHT or HGM contents approach 8 or 20 wt%, respectively, and the minimum dielectric constant (εr) and dielectric loss (tan δ) of PEKK/SHT or PEKK/HGM films decrease visibly with decreasing SHT densities. By filling with 0.46 g cm−3 mean density of SHT or HGM fillers, the minimum εr and tan δ of PEKK/SHT films are somewhat smaller than those of PEKK/HGM films. The linear coefficient of thermal expansion (LCTE) values of PEKK/SHT or PEKK/HGM films reduce and their onset degradation temperature values increase gradually with increasing SHT and HGM contents. Low εr/tan δ (2.11/0.0022 and 2.2/0.0027 at 1 MHz), LCTE (35.5 × 10−6 and 31.2 × 10−6 °C−1) and excellent heat‐resisting properties favorable for sixth generation (6G) ultrarapid communication are realized for appropriately prepared PEKK/SHT and PEKK/HGM substrate films. The free‐volume‐hole characteristics of PEKK/HGM or PEKK/SHT films approach a maximum as SHT or HGM contents reach an optimum value of 8 or 20 wt%, respectively. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

A single crystal of L-lysine iodide (LLI) was created by utilizing a room-temperature slow evaporation approach. The monoclinic of the crystal lattice system was confirmed by estimating the lattice parameters of the synthesized single crystals using single crystal X-ray diffraction analysis. The crystalline structure and planar indexing were confirmed by powder XRD. In order to confirm that the produced LLI crystals included functional groups, the FT-IR spectra were analyzed. Spectra of visible, near-infrared, and ultraviolet light (ranging from 200 to 1100 nm) were analyzed and the cutoff wavelength of 268 nm. Vickers microhardness tester was used to find out how strong the formed crystal was mechanically stable. From 50 Hz to 3 MHz, the dielectric response of the manufactured crystal was studied at different temperatures. Thermogravimetric analysis used to look at the thermal characteristics. Human pathogens were the primary focus of antimicrobial research. Using scanning electron microscopy (SEM), the surface characteristics of the generated crystal were examined. The produced LLI crystal was recommended for use in opto-electronic and biological applications. [ABSTRACT FROM AUTHOR]

Glycine manganese sulphate (GMS) crystals are produced by a slow evaporation technique at room temperature. This is confirmed that triclinic of the crystal lattice system by using single crystal X‐ray diffraction analysis and to determine the lattice parameters of the synthesised crystals. Powder XRD is used to confirm the planar indexing and crystalline structure. The Fourier Transform Infrared (FT‐IR) spectra are examined to verify that functional groups are present in the generated GMS crystals. By establishing a cut‐off wavelength of 253 nm, spectra of visible, near‐infrared, and Ultra Violet (UV) light from 200 to 1100 nm are analyzed. At frequencies ranging from 100 Hz to 8 MHz, the grown crystal's dielectric response is studied. Vickers microhardness tester is utilized to find out how strong the grown crystal is mechanically. Photoluminescence (PL) investigations often aim to detect crystal formation faults and contaminants. Etching analysis is used to find surface flaws and dislocations on the formed crystal's surface. The internal surface property of the produced crystal is investigated with scanning electron microscopy (SEM). The findings contradicted each other, suggesting that the created GMS crystal be used in opto‐electronic device applications. [ABSTRACT FROM AUTHOR]

Ferrite compounds have gained scientific attention for their multifunctional attributes. This investigation explores the structural, optical, dielectric and conductivity properties of polycrystalline γ-Fe 2 WO 6 synthesized by the solid state route. The X-ray diffraction confirmed the orthorhombic structure and single-phase formation, while the electron microscopy showed uniform distribution of dense micrometer-sized grains in γ-Fe 2 WO 6. The FTIR spectroscopy analysis validated the presence of active stretching and bending modes, signifying oxygen anion vibration at both Fe and W sites. The simultaneous presence of Fe2+ and Fe3+ ions in the matrix, as confirmed by X-ray photoelectron spectroscopy (XPS), results in an augmented optical energy band gap and contributes to dielectric permittivity due to the charge carrier hopping mechanism between the trap sites. The compound manifests semiconductor attributes, evident in its indirect optical band gap measuring 1.7 eV. It is observed that the compound has effectively degraded the Methylene Blue (MB) under the visible light within 40 min with a degradation efficiency up to 63 %. The material's electrical conductivity, follows the Jonscher's power law, signifies its semiconductor nature and adheres to the Small Polaron tunneling model for charge conduction between neighboring sites. The impedance (Z′) curves exhibit dielectric relaxation (≤ 10 kHz) with a similar activation energy to the dc conductivity study. The activation energy, determined from both the impedance and conductivity analyses, indicates a connection with the migration of oxygen vacancies within the material. Our observation reveals the presence of oxygen vacancies, which possibly act as in-gap electron traps, enhancing the correlated optical and ac conductivity properties, making it an appealing material for diverse multifunctional applications. [ABSTRACT FROM AUTHOR]

In this work, Gadolinium (Gd3+) substituted Co–Cu–Cr (CCC) SFs with the chemical formula Co 0.5 Cu 0.5 Cr 0.5 Gd x Fe 1.5-x O 4 (x = 0.00, 0.05, 0.10, 0.15, and 0.20) were synthesized via the self-combustion process. The single-phase matrix of the Gd3+ substituted CCC SFs was verified using X-ray diffraction (XRD). The crystallite size (D) of Gd3+ doped CCC SFs was reduced from 51.20 nm to 36.27 nm with increasing Gd3+ doping. The addition of Gd3+ in the CCC SFs lattice enhanced specific surface area (S) from 22.11 cm2/g to 28.57 cm2/g. The energy bandgap (E g) was increased from 4.83 eV to 5.40 eV and revealed an inverse relation with crystallite size. The tangent loss (tan δ), dielectric loss (ε ″), dielectric constant (ε ′), and ac conductivity (σ a c ) of Gd3+ doped CCC SFs exhibit frequency-dependent behaviour. The behaviour of these dielectric properties has been analyzed using both Koop's theory and the Maxwell-Wagner model. Moreover, it was found that the ε ′ was enhanced, while σ a c and tan δ w as reduced with the doping of Gd3+ in CCC SFs. The saturation magnetization and microwave operating frequency were increased with the doping of Gd3+ in CCC SFs. Because of their diverse dielectric and magnetic properties, the Gd3+ doped CCC SFs have considerable potential for different applications, including microwave absorption materials, switching high-frequency devices, and microwave frequency-operating devices. [ABSTRACT FROM AUTHOR]

Microwave absorbing materials play an increasingly important role in modern electronic warfare technology for enhancing electromagnetic compatibility and suppressing electromagnetic interference. High‐entropy ceramics (HECs) possess extraordinary physical and chemical properties, and more importantly, the high tunability of multi‐component HECs has brought new opportunities to microwave absorbing materials. Rich crystallographic distortions and multi‐component occupancies enable HECs to have highly efficient microwave absorption properties, excellent mechanical properties, and thermal stability. Therefore, the structural advantages of HECs are integrated from comprehensive perspectives, emphasizing on the role of dielectric and magnetic properties in the absorption phenomenon. Strategies are proposed to improve the microwave absorption capacity of HECs, including composition optimization, microstructure engineering, and post‐treatment technology. Finally, the problems and obstacles associated with high‐entropy materials (HEMs) research are discussed. The innovative design concepts of high‐entropy microwave absorbing ceramics are highlighted. [ABSTRACT FROM AUTHOR]

For the first of its kind, Cr 3 + -substituted calcium hexaferrite (CaCrxFe 1 2 − x O 1 9 (x = 1 , 3, 5 and 7)) nanoparticles (NPs) were synthesized via a facile, economical, eco-friendly lemon juice extract mediated green solution combustion method. The samples were calcined followed by characterization. The Bragg reflections confirm the formation of a single phase M-type hexaferrite crystal structure. No other impurity or mixed phases are observed even after the substitution of Cr 3 + to the host matrix. Meanwhile, the crystallite size decreases from 29.44 to 19.92 nm with an increase in the substitution of Cr 3 + ions. The surface morphological analysis shows the presence of agglomerated irregularly shaped NPs. The direct energy band gap estimated using Wood and Tauc's relation depicts the decrease in energy band gap from 2.98 to 2.74 eV with an increase in the substitution of Cr 3 + ions. These Cr 3 + -substituted calcium hexaferrite NPs were predicted to be useful in high-frequency applications based on structural, dielectric, and magnetic studies. [ABSTRACT FROM AUTHOR]

In this work, an attempt is made for improving the piezoelectric properties of a lead-free (Na 0. 5 K 0. 4 8 5 Li 0. 0 1 5) (Nb 0. 9 8 V 0. 0 2) O3 ceramic system by doping manganese in it. The Rietveld analysis of XRD micrographs of the ceramics indicates the samples crystallizing into 99.86% of orthorhombic phase and very small traces of tetragonal phase around room temperature. The Curie temperature ( T c ) is hardly affected by the incorporation of Mn 4 + into the system. At the manganese concentration of 0.02 wt.%, the ceramic system attains the peak values in its density, dielectric constant at room temperature ( ε RT ), planar electromechanical coefficient ( k p) , piezoelectric coefficient ( d 3 3 ), and remnant polarization ( P r ). The optimum piezoelectric properties of k p = 4 3 % and d 3 3 = 1 9 3 pC/N are observed for this composition. The study reveals that the modification of (Na 0. 5 K 0. 4 8 5 Li 0. 0 1 5 ) (Nb 0. 9 8 V 0. 0 2) O3 with an appropriate quantity of Mn 4 + can produce the desired changes in the crystallographic properties and densification so as to eventually improve its piezoelectric properties. [ABSTRACT FROM AUTHOR]

A series of compounds with the general formula A2MB2O6 (A=Zn, Ba, Pb; B=Pb, Ba, Zn, Cu) related to the kotoite structure has been prepared employing high‐temperature solid state methods. The substitution of transition elements in place of Zn2+ ions resulted in colored compounds. The optical absorption spectra could be explained based on Tanabe‐Sugano diagram and allowed d‐d transitions. Dielectric studies on Ba2ZnB2O6, (Ba1.5Pb0.5)ZnB2O6, PbZn2B2O6, Pb1.5Zn1.5B2O6, BaZn2B2O6 and Pb2CuB2O6 at room temperature indicate reasonable values at low frequencies, which decrease on increasing frequencies. Magnetic study of synthesized single‐phase compounds BaZnCoB2O6 and Pb2CuB2O6 have been performed. The substitution of Eu3+, Tb3+ and Tm3+ in place of Ba2+ in Ba2ZnB2O6, gives rise to the expected emission of red, green and blue colors. Suitable modifications of the different phosphors in Ba2ZnB2O6, resulted in white‐light emission in Ba2ZnB2O6. The Pb2CuB2O6 compound was found to be a good catalyst in the ipso‐hydroxylation of arylboronic acids. [ABSTRACT FROM AUTHOR]

Due to increasing global energy demands and environmental concerns, the search for alternative and environmentally friendly energy sources is of paramount importance. Solid oxide fuel cells (SOFCs) have emerged as a promising solution thanks to their high efficiency and minimal environmental impact. In this regard, perovskite oxides, with their unique properties, have attracted significant attention. This study investigates the dielectric dispersion, electrical features, scaling behavior, and optical defects of Ca 0.67 La 0.22 Ti 0.85 Cr 0.15 O 3 with x = 0.15, CLT 0.85 Cr 0.15. The presence of a vacancy in the A-site is denoted by the square in the formula. Relaxation phenomena were analysed using dielectric and modulus formalism, while the conductivity mechanism was explored through electrical conductivity measurements. The optical defects of CLT 0.85 Cr 0.15 were analysed using electron paramagnetic resonance (EPR) spectroscopy. The findings revealed the formation of Cr3+–VO center defects. These defects serve as sources of in-gap electron traps, thereby enhancing the optical properties of CLT 0.85 Cr 0.15 , making it as a compelling material for various optical applications. The power density increased with temperature, reaching 0.73 W/cm2 at 850 °C, suggesting that CLT 0.85 Cr 0.15 could be a promising electrolyte for IT-SOFCs. The peak in power density correlated with temperature due to thermal effects on ion motion. However, the open circuit voltage decreased with temperature increase, due to increased oxygen vacancies and electron/hole conduction in CLT 0.85 Cr 0.15. The findings suggest that perovskite materials could revolutionize SOFCs technology, paving the way for more efficient and environmentally friendly energy solutions. [ABSTRACT FROM AUTHOR]

In this study, the sol-gel auto-combustion (SGAC) approach was used to synthesis praseodymium (Pr3+) substituted Zinc-Cobalt (ZC) ferrites, having general formula Co0.7Zn0.3PrxFe2−xO4 (x = 0.0, 0.05, 0.10, 0.15, and 0.20). X-ray Diffraction (XRD) analysis revealed a secondary phase (PrFeO3) with a composition of x ≥ 0.10 and the presence of FCC structure. The crystallite size (D) of Pr3+ doped ZC SFs decreased from 17.36 nm to 12.44 nm as the amount of Pr3+ doping increased. Additionally, the lattice constant saw an enhancement from 8.34 a (Å) to 8.96 a (Å) with the incorporation of Pr3+ into the ZC SFs. XRD and FTIR analysis verified the replacement of Pr3+ into ZC SFs. Inhomogeneous grain size distribution was seen in samples by applying the Scanning Electron Microscopic (SEM) technique. It was discovered that the dielectric loss decreased with the applied frequency, which is helpful for high frequency device applications. The substitutions of Pr3+ ions resulted in remanence (Mr (emu/g)), saturation magnetization (Ms (emu/g)) and coercivity (Hc (Oe)) maximum at x = 0.00 and minimum for x = 0.20 in ZC SFs, respectively. The maximum microwave frequency in GHz maximum for x = 0.00 (18.8 (GHz)) and minimum at sample x = 0.20 (7.86 (GHz)). According to the findings of our research, Pr3+ substituted spinel ferrites appear to be very useful in radar, satellite communication, space communication, and microwave frequency applications. [ABSTRACT FROM AUTHOR]

Environment-friendly Ba0.95Ca0.05Ti0.91Sn0.09-xZrxO3 ceramics, with x = 0.00 and 0.01 (BCTSZx) were prepared through a standard solid-state sintering process. The diffusion coefficient estimated from the Santos-Eiras fit of ε r -T plot implies that the ferroelectric-paraelectric transition is a diffuse type. Well-saturated and fatigue resistant P-E hysteresis loops were obtained at room temperature (RT). The energy-storage density (Wrec) and the associated efficiency (η) were obtained from P-E loops data. When applying a relatively losw electric field of 30 kV/cm, a large value of adiabatic temperature change (∆T = 0.73 K), high values of electrocaloric responsivity (ξ = 0.247*10−6 K·m·V−1) and coefficient of performance (COP = 12.26) were obtained in BCTSZ ceramic. In addition, the pyroelectric figures of merit (FOMs) were calculated. The density of pyroelectric energy harvesting increased from 206 to 237 kJ/m3 when the Olsen cycle was operated at temperatures between 25 and 100 °C and an electric field between 0 and 30 kV/cm. The results indicate that the increase in the grain size significantly enhances the dielectric, electrocaloric and pyroelectric properties. This research not only presents a novel technique for generating high-performance ceramic for refrigeration devices, but also expands the field of applications for BaTiO3-based lead-free ferroelectrics for energy storage applications. [ABSTRACT FROM AUTHOR]

This work demonstrates the fabrication, characterization, and energy storage capacity of high calcium-doped strontium titanate thick films (Sr0.60Ca0.40TiO3) for the first time. The thick films were fabricated using the screen-printing technique and densified using uniaxial pressing. The effect of densification on the structural, morphological, and surface chemical compositional of the materials was studied. The densified thick film revealed a notable frequency stability of dielectric permittivity (ε′) ≈ 198 with a low dielectric loss tangent (tanδ) in the order of 10− 3 between 100 Hz and 1 MHz and was characterized by slim P-E loops signifying its paraelectric nature. A high energy recovery density (Ue) of 4.1 J/cm3 and a high energy efficiency of 96% were simultaneously reached. [ABSTRACT FROM AUTHOR]

The application of variable angle spectroscopic ellipsometry (VASE) to the characterization of thin films is very important because it facilitates the understanding of their physical and optical properties. To prepare a series of film samples consisting of TiO2:ZrO2 on a TiN/Si substrate, we employed the SYBILLA P200 equipment (manufactured by ABCD Technology) through the process of Chemical Beam Vapor Deposition (CBVD). TiO2:ZrO2 on TiN/Si thin films is a composite material that has gained significant attention in various technological applications, particularly in the field of thin film coatings on semiconductor substrates like TiN/Si. TiO2:ZrO2 thin films exhibit excellent dielectric properties and good thermal stability, making them suitable for various electronic and semiconductor applications. From FESEM and EDX analysis, it is found that with increase of Ti/Zr atomic ratio, grain size increases. Ellipsometric analysis reveals increase in film thickness and refractive index with increase in Ti/Zr atomic ratio. As the film continues to grow, changes in its microstructural phase led to a transition from a monolayer physical ellipsometry model to a bilayer physical model. This transition is due to the appearance of inhomogeneity in the TiO2:ZrO2 thin film. Dynamic fits obtained using a two‐layer physical model and a Cauchy–Lorentz optical model show three distinct phases in the film growth phase: a nucleation phase, a fusion phase, and a continuous layer phase. Although our proposed model shows satisfactory performance in most cases, the determination of the refractive index can be problematic for very thin thicknesses. The developed VASE modeling process should be able to generate TiO2:ZrO2characterization on TiN/Si substrate films using comparable physical and optical modeling considerations. [ABSTRACT FROM AUTHOR]

In this paper, we describe the synthesis of cerium molybdate (Ce 2 (MoO 4) 3) and different compositions of Bi-doped cerium molybdate (Ce 2-x Bi x (MoO 4) 3) where x = 0.01, 0.03, 0.05, 0.07, and 0.09, through simple co-precipitation method. The synthesized materials were optically, structurally, and morphologically characterized by various sophisticated techniques, including UV–visible, FTIR, Raman, PXRD, BET, and SEM-EDX. Upon addition of bismuth, the optical band gaps are reduced from 3.35 eV (Ce 2 (MoO 4) 3) to 2.83 eV Ce 1.93 Bi 0.07 (MoO 4) 3. The charge storage potential and AC conductivity of the synthesized materials were investigated through dielectric studies where the dielectric constant increased by increasing dopant concentration up to 7 %. At 20 Hz, Ce 1.93 Bi 0.07 (MoO 4) 3 showed a significantly greater dielectric constant (3.597 × 106) compared to undoped Ce 2 (MoO 4) 3 (3.262 × 105). Similarly, the AC conductivity of Ce 1.93 Bi 0.07 (MoO 4) 3 increased up to 4.758 S m−1 compared to the undoped Ce 2 (MoO 4) 3 (2.270 S m−1) at 20 MHz. The photocatalytic efficiency was investigated against diclofenac potassium, which also considerably improved by increasing bismuth content. The maximum photodegradation efficiency of 87.9 % was observed for Ce 1.93 Bi 0.07 (MoO 4) 3 in 180 min under UV light irradiation at optimized conditions (pH = 4, catalyst dosage = 20 mg, and initial concentration of drug = 5 mg L−1). The photocatalytic reaction followed pseudo-first-order kinetics with a rate constant of 0.0108 min−1 with stability up to five successive runs of photocatalytic activity indicating its good recyclability. These findings suggest that Bi-doped cerium molybdate could be used as a promising material for photocatalysis and energy storage devices. [ABSTRACT FROM AUTHOR]

The samples including Li 0.1 Co 0.8 Fe 2. 1 O 4 (LCFO) spinel ferrite (SF) and LCFO SF/graphene oxide (GO = 10 wt%, 15 wt%, and 20 wt%) nanocomposite were fabricated via the self-ignition route by following the bath ultra-sonication method. Their structural, morphological, and compositional properties were analyzed using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Energy-dispersive X-ray (EDX) spectroscopy, respectively. Moreover, the dielectric and magnetic properties at 300 K were studied using an impedance analyzer (IA) meter and vibrating sample magnetometer (VSM), respectively. All LCFO SF and GO-based LCFO nanocomposites exhibited a pure spinel matrix. The crystallite size was increased by the GO addition in the LCFO SF sample. The morphological analysis showed the non-uniform distribution of particles. The dielectric constant and loss exhibited behaviour consistent with Maxwell-Wagner interfacial polarization. The low tangent loss was observed at high frequency and ac conductivity analysis was increased with increasing the GO content. A slight enhancement in saturation magnetization was observed at 300 K with the addition of GO in LCFO SF. Hence, doping with GO offers a means to tune the dielectric, and magnetic response of the LCFO SF sample and is the best candidate for potential high-frequency application. [Display omitted] • The LCFO SF and LCFO/GO nanocomposites were prepared via the self-ignition route with an ultra-sonication technique. • The crystallite size was increased from 30 nm to 54 nm. • FTIR analysis along with XRD analysis also confirmed the spinel matrix. • SEM and TEM micrographs indicated the non-uniform distribution and agglomeration with the increasing GO. • The increase in GO leads to an improvement in the dielectric response. • The saturation magnetization was increased with the addition of GO. • The combination of LCFO SF with GO enhanced the dielectric, and magnetic properties, offering a candidate for high-frequency applications. [ABSTRACT FROM AUTHOR]

In this project, the oxidative chemical polymerization method is used to prepare polymer composite that consisting of polypyrrole polymer (PPy) and iron oxide nanoparticles (Fe2O3NPs). Then deposited this blend (PPy/Fe2O3) onto the PET substrate to creating flexible nanocomposite PET/(PPy/Fe2O3). Analyzing the samples using X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) proves that the composite was effectively formed. With varying Fe2O3 ratios, the dielectric parameters of PET polymer and PET/(PPy/Fe2O3) composite have been documented at frequencies of 40–5.6 MHz. The surface properties were significantly enhanced by irradiation. The surface free energy increases from 41.36 mJ/m2 to 66.23 mJ/m2 and water contact angle reduces from 58.36° for PET to 39.25°. The results demonstrated that the composite surface characteristics were enhanced as the concentration of Fe2O3 changed. The obtained data showed that the fabricated samples have better properties than the PET films that can be utilized in many applications as capacitors and storage devices. a SEM of PET, b SEM of PPy/Fe2O3, c SEM of PET/(PPy/Fe2O3, d contact angle with ratios of Fe2O3 and e surface free energy with ratios of Fe2O3 [ABSTRACT FROM AUTHOR]

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This work presents a 2D tellurium (Te)‐based diode that exploits the doping achieved by atomic layer deposited (ALD) Al2O3 to enhance its rectifying performance. The proposed device comprises a Schottky junction that is dielectric‐doped to significantly reduce the reverse bias current. A boosted current responsivity four times higher compared to that of undoped devices is achieved, maximizing the performance for radio frequency (RF) power detectors. The application measurement results demonstrate sensitivities as low as −45 dBm, and at −30 dBm RF input power outstanding tangential responsivities up to 6.5 kV W–1, 4.3 kV W–1, and 650 V W–1 at 0.5, 1, and 2.5 GHz, respectively, while reaching linear dynamic range (DR) of over 30 dB. These are the highest reported values for 2D‐based material devices by almost two orders of magnitude. Furthermore, the DR is ≈10 dB larger compared to state‐of‐the‐art power detectors based on bulk semiconductors. [ABSTRACT FROM AUTHOR]

Dielectrics are non‐conducting substances that are primarily utilized to hold electric charges. These materials are widely employed in the field of chemical mechanical, civil and structural engineering, because of their inherent insulating properties. Besides these domains, dielectric materials are also used in electrical and electronic applications. Dielectric materials have shown an ever‐increasing potential in recent years in the fabrication of antennas, sensors, and optical devices that are extensively utilized for on‐body, environmental, robotics, and biomedical applications. With inherent electrostatic shielding, insulation, and dielectric relaxations, these materials are used in intelligent electronic devices used for biomedical applications, smart devices, vehicles, and future IoT applications. Numerous applications necessitate multiple kinds of dielectric, classified based on their polarization, flexibility, thickness, dielectric constant, and specific application. In this extensive research review, the characteristics and various aspects of dielectric materials are discussed, followed by a thorough and detailed review of flexible dielectrics and their usage in flexible electronics. Additionally, the practicality and applications of these materials which come from a variety of publications in the literature are also discussed. Moreover, in‐depth study of dieletrics in sensors and RF applications are performed. [ABSTRACT FROM AUTHOR]

The structural, morphological, magnetic, and dielectric properties of lanthanum substituted nickel ferrite (NiLaxFe2−xO4) nanoparticles have been reported in this article. The amount of lanthanum substitution in NiLaxFe2−xO4 sample was varied from x = 0.025 to 0.125. The nanocrystalline Ni–La ferrites were synthesized using a solution combustion reaction (SCR) method. The orthorhombic crystal system of space group Pnma (62) is shown as the single-phase in all samples through structural investigation utilizing an X-ray diffraction (XRD) pattern. The observed trend indicates a positive correlation between the concentration of La and the corresponding rise in the predicted crystallite size values, which range from 60.5 nm to 65.2 nm. The nanoscale of the surface morphology has been confirmed by the utilisation of field emission scanning electron microscopy (FESEM). Energy dispersive X-ray (EDAX) mapping provides the compositional evidence for the prepared Ni–La ferrites. In addition, X-ray photoelectron spectroscopy (XPS) determines the ionic state of the individual atoms present in these samples. It reveals that there are no changes in the ionic state of the parent component atoms by substituting La. EDAX and XPS evidence the purity of prepared NiLaxFe2−xO4 samples without any other impurity elements. By regulating the composition of dopants, this research can substantiate the superparamagnetic characteristics of ferrites. The paramagnetic nature of lanthanum atoms involves in reducing the coercivity value. The dielectric measurement on NiLaxFe2−xO4 samples reveals that La3+ substitution effectively influence the electro-transport properties. [ABSTRACT FROM AUTHOR]

AbstractOur research described in this report describes our advanced thermo-electric characterization of hydroxyapatite (HA) and multi-walled carbon nanotube (MWCNT) reinforced polyether ether ketone (PEEK) polymer composites. The incorporation of HA and MWCNTs was aimed to enhance the thermo-electric properties of PEEK while maintaining its biocompatibility. Three different methodologies were followed for development of the polymer nanocomposites with the effect of varying the methodologies investigated in the present study. FTIR analysis showed the presence of HA, MWCNT and PEEK, confirming the formation of the nanocomposite. HA and MWCNT addition enhanced the dielectric constant and conductivity compared to pure epoxy. This corresponds to enhanced interfacial polarization and charge transfer capabilities. Differential Scanning Calorimetry (DSC) analysis confirmed the modification of the glass transition temperatures, with the addition of HA and MWCNT indicating enhanced thermal stability as well as resistance to degradation. This research, we suggest, paves the way for innovative materials that bridge the gap between functionality and biocompatibility in advanced engineering applications. [ABSTRACT FROM AUTHOR]

Ca and Cs doped barium titanate lead-free ceramic with the formula Ba 0.75 Ca 0.2 Cs 0.05 TiO 3 has been prepared by the solid-state reaction method. X-ray diffraction (XRD) confirms the crystallization of the sample in a tetragonal structure with a P 4 mm space group. The phase purity and grain morphology were evaluated using X-ray diffraction and scanning electron microscopy (SEM). The material exhibits a primary phase of Ba0.75Ca0.2Cs0.05TiO3 with a minor secondary phase of BaO 2 , and the average grain size is determined to be 1.66 μm. Using non-destructive complex impedance spectroscopy (CIS), we extensively studied the electrical behavior, including complex impedance (Z*), complex modulus (M*), electrical conductivity, and relaxation mechanisms, of Ba 0.75 Ca 0.2 Cs 0.05 TiO 3 over a wide temperature (85 K–290 K) and frequency range. The ac conductivity analysis reveals that the dominant conduction mechanism is the non-overlapping small polaron tunneling (NSPT) model. The impedance analysis indicates a single semi-circle in the real and imaginary parts, suggesting a single relaxation mechanism. Additionally, the activation energy was calculated to be approximately 0.0489 eV. These findings contribute to the understanding of the structural and electrical properties of Ba 0.75 Ca 0.2 Cs 0.05 TiO 3 , highlighting its potential applications in electronic devices such as capacitors, thermistors, and ferroelectric random access memories (FRAMs). [ABSTRACT FROM AUTHOR]

ABSTRACT A novel superstrate‐based Vivaldi antenna design characterized by high‐gain and wideband performance is presented. The proposed design configuration features a Vivaldi antenna positioned between high dielectric superstrate (Rogers 6010, εr = 10.2) with copper etched off on both sides and an FR4 substrate that has copper etched on one side only. The introduction of a high permittivity dielectric material above and a reflector below the Vivaldi antenna enables favorable resonance conditions for achieving high‐gain operation. The measured antenna exhibits a peak gain of 17 dBi at 10 GHz, covering an operating frequency range of 6–20 GHz. It also features a narrow half‐power beamwidth and low side lobe level radiation patterns. Unlike existing studies, which rely on metamaterials, electromagnetic bandgap structures, and frequency selective surfaces for gain enhancement, our design employs high‐dielectric constant superstrates. This approach increased the antenna's peak gain by 10 dB. Also, the proposed configuration act as a radome protecting the antenna from Environment. [ABSTRACT FROM AUTHOR]

In the present work the atomic, electronic and optical properties of two-dimensional graphene, borophene, and boron carbide heterojunction bilayer systems (Graphene–BC3, Graphene–Borophene and Graphene–B4C3) as well as their constituent monolayers are investigated on the basis of first-principles calculations using the HSE06 hybrid functional. Our calculations show that while borophene is metallic, both monolayer BC3 and B4C3 are indirect semiconductors, with band-gaps of 1.822 eV and 2.381 eV as obtained using HSE06. The Graphene–BC3 and Graphene–B4C3 bilayer heterojunction systems maintain the Dirac point-like character of graphene at the K-point with the opening of a very small gap (20–50 meV) and are essentially semi-metals, while Graphene–Borophene is metallic. All bilayer heterostructure systems possess absorbance in the visible region where the resonance frequency and resonance absorption peak intensity vary between structures. Remarkably, all heterojunctions support plasmons within the range 16.5–18.5 eV, while Graphene–B4C3 and Graphene–Borophene exhibit a π -type plasmon within the region 4–6 eV, with the latter possessing an additional plasmon at the lower energy of 1.5–3 eV. The dielectric tensor for Graphene–B4C3 exhibits complex off-diagonal elements due to the lower P3 space group symmetry indicating it has anisotropic dielectric properties and could exhibit optically active (chiral) effects. Our study shows that the two-dimensional heterostructures have desirable optical properties broadening the potential applications of the constituent monolayers. [ABSTRACT FROM AUTHOR]

The structural, microstructural, dielectric, optical, ferroelectric, and magnetic properties of cobalt doped barium calcium titanate (BCT) (Ba 0.80 Ca 0.20 Ti 1-x Co x O 3 with x = 0.000, 0.005, 0.010, 0.015, and 0.020) ceramics have been reported in this paper. The ceramic samples were prepared by the conventional solid-state reaction method. For all of the prepared samples, the tetragonal structure with the space group P 4 mm has been confirmed using the refinement method through Rietveld refinement of X-ray diffraction patterns. Field Emission Scanning Electron Microscopy (FESEM) micrographs revealed that the average particle size exists in micrometre range (0.3–0.8) μm. Optical studies revealed a gradual decrease in the energy bandgap from 3.31 eV to 2.71 eV with increasing doping concentration. A decreasing trend was observed in the dielectric characteristics of the material with changing frequencies at room temperature. Ferroelectric (P-E loops) analysis displayed an increase in both remnant polarization and maximum polarization of the ceramic with the increasing applied electric field. The highest value for the energy storage efficiency (η) was calculated to be 20.51 %. Magnetic analysis conducted at room temperature revealed the enhancement in ferromagnetism with the increase in doping concentration. [ABSTRACT FROM AUTHOR]

Iron (Fe)-incorporated zinc oxide (ZnO) nanoparticles (NPs) were synthesized via chemical precipitation technique and studied using powder X-ray diffraction (PXRD), field emission scanning electron microscopy (FESEM), and UV–vis diffuse reflectance spectroscopy. PXRD analysis reveals a hexagonal wurtzite structure for all the synthesized samples. UV–visible measurements demonstrate a reduction in the bandgap of ZnO with an increase in Fe concentration. The ZnO and Fe-incorporated ZnO NPs are studied for the degradation of organic textile dye under visible light irradiation. All the nanoparticles are thoroughly investigated using impedance and dielectric measurements in the frequency range of 20 Hz to 1 MHz. The results obtained are compared, interpreted, and presented in this paper. [ABSTRACT FROM AUTHOR]

Herein, niobium pentoxide (Nb2O5) nanosheets grown by the thermal evaporation technique under a vacuum pressure of 10− 5 mbar are treated as terahertz band filters. The amorphous thin layers of Nb2O5 exhibited high light transmittance and showed optical absorption within an energy band gap of 3.68 eV. The band gap contained wide-extended band tails with Urbach energy of 2.27 eV. As terahertz optical band filters, Nb2O5 nanosheets displayed a cutoff frequency of ~ 1.0 THz in the spectral range of 1.15–3.37 eV. Larger exciting light signals in the ultraviolet range increased the terahertz cutoff frequency from 1.2 THz to 170 THz as the light energy increased from 3.38 eV to 4.20 eV, respectively. Additionally, the fitting of the optical conductivity using the Drude-Lorentz model has shown that the optical conduction in Nb2O5 is associated with six optical oscillators. Two of these oscillators are dominant in the infrared range of light, three are active in the visible range, and one is sensitive to ultraviolet light radiation. The drift mobility of the charge carriers in the films varied in the ranges of 1.76–3.67 cm2/Vs. Electrical verification of the optical results was actualized through the design of Yb/p-Nb2O5/Ag band filters. This electrical device showed a negative capacitance effect and exhibited a cutoff frequency of 1.0 THz when a driving signal of frequency 0.597 GHz was imposed between the terminals of the device. These features prove the suitability of the terahertz band filters of Nb2O5 nanosheets for use as optical and electrical filters with an extremely wide range of tunability. [ABSTRACT FROM AUTHOR]

Ferroelectric (FE) materials and their advancements have piqued the scientific community's interest greatly since they provide numerous fascinating processes in addition to being used in devices. Among them, we have studied Mn and Sn co-doped PZT and Pb (Zr0.52Ti0.48) O3 as PZT, an extremely intriguing FE. The structure and phase purity of all the samples are determined by x-ray diffraction techniques. All the samples show a very good microstructures and the average grain size is found to be decreased with ion incorporation. The UV-Vis spectra show how doping reduces optical band gaps. Parallel resistance (R)-capacitance (C) circuits have been used to analyze the relationship between microstructure and electrical characteristics. The microscopic processes in various PZT samples with dilute magnetic cations at A-sites, B-sites, and/or both sites at the morphotopic phase boundary are established from the detail impedance, modulus, and ac conductivity of the samples as a function of temperature (300 –500 °C) and over a range of frequency (100 Hz to 1 MHz). Additionally, the framework of the Jump relaxation model and the Jonscher power law are used to study the ac-conductivity data. [ABSTRACT FROM AUTHOR]

In the present study, the effect of varying titanium dioxide (TiO2) nanoparticles on the dielectric, thermal, and corrosion characteristics of PI-based composites prepared by spark plasma sintering was investigated. The results obtained revealed that the TiO2 nanoparticles were uniformly dispersed within the PI matrix. Addition of TiO2 into the neat PI markedly reduced its dielectric constant and electrical conductivity by 72.7% and 82.3%, respectively, as well as enhancing its breakdown strength by 16.7% at 8 wt% TiO2 loading. The nanocomposites depict better thermal stability and heat-resistance index characteristics when compared to the PI. Additionally, the produced nanocomposites exhibit improved corrosion resistance than that of the neat PI. The remarkable improvement in the dielectric, thermal stability, and corrosion resistance of the nanocomposites is achieved by better dispersion of the TiO2 particles in the polymer matrix. The enhancement in properties suggests TiO2/PI-based nanocomposites potential for a variety of applications in electrical insulation, thermal management, and harsh environment. [ABSTRACT FROM AUTHOR]

Polymer specifications' optimization for tailored applications is desirable for enhanced applicability. In this research, we have successfully prepared the PMMA/metal oxide (0.1 wt% CeO2, and TiO2) through a feasible casting method. The implications of the metal oxides incorporation were explored. XRD reveals the successful formation of the composites, with 20 nm crystallite size of both composites. FTIR reinforces the intended composite formation with significant bands allocation. Optical bandgaps for PMMA/CeO2 and PMMA/TiO2 are 2.91 and 3.15 eV for direct transitions, respectively. For indirect transitions, the bandgap is around 3.33 eV for both. Other optical parameters were calculated as real and imaginary dielectric constants. THz displays a linear manner with a somewhat more PMMA fixed band due to the inharmony of intermolecular vibration mode. Dielectric studies manifest polymer loss spectra with multiple non-Debye relaxation progressions β, and γ relaxations alongside MVS polarization for films containing CeO2 or TiO2. The synthesized nanocomposites indicated antibacterial influence against (S. aureus, and B. subtilis) as Gram-positive bacteria, and (E. coli, and K. pneumoniae) as Gram-negative bacteria, (C. albicans) (A. niger) as yeast and Fungi strains. The PC samples show a high impact against Gram-positive bacteria, yeast, and Fungi strains, while PT samples show a high impact against Gram-negative bacteria. [ABSTRACT FROM AUTHOR]

The integrable substrate for THz modulation directly influences both the quality of films and THz absorption. Currently, the available THz substrate candidate library is still not clear. Here, we have carried out a systematic investigation of commonly used commercial substrates, including Si, quartz SiO2, MgO, Al2O3, GdScO3 and TbScO3 in the range of 0.4–1.6 THz. It is found that low resistance Si, TSO and GSO are certainly not appropriate for THz light modulation due to their relatively higher absorption and dielectric constant, while the rest show better THz transmittance, low refractive index and loss. However, the dielectric constant and refractive index of high resistance Si are generally two times larger than quartz SiO2, Al2O3 and MgO. Compared with Al2O3 and MgO, quartz SiO2 shows at least 50% lower dielectric constant, refractive index and absorption, making it the best candidate. Our research is believed to build the rich substrate candidate library for THz range light modulation. [ABSTRACT FROM AUTHOR]

Metasurfaces can replace bulk optical components in a more compact form factor in applications including communication systems, sensors, and manufacturing technology. However, their design and fabrication is challenging due to competing demands of selecting meta-atoms that simultaneously provide the required amplitude and phase modulation while being robust to fabrication errors. Here, we develop two design heuristics to assist with the down-selection of meta-atoms into sensitivity-informed libraries, based on either selecting meta-atoms with minimal sensitivity or minimizing the relative sensitivities between meta-atoms. We evaluate both methods on a polarization-dependent phase mask and compare the resulting phase and intensity errors. [ABSTRACT FROM AUTHOR]

The effect of boron doping on dielectric properties was examined using β-SrTa2O6:xEu3+ (x = 1.5 mol%, 3 mol%, 5 mol%, 10 mol%), β-SrTa2O6:xEu3+, yB3+ (x = 1.5 mol%, 3 mol%, 5 mol%, 10 mol%, y = 10 mol%) and BaTa2O6:xEu3+, yB3+ (x = 10 mol%, y = 0 mol%, 5 mol%, 15 mol%, 30 mol%, 50 mol%, 70 mol%, 100 mol%) tungsten bronze ceramics produced by the solid-state reaction method. X-ray diffraction (XRD) results of all the β-SrTa2O6 and BaTa2O6 samples showed that they retained a single-phase structure. In scanning electron microscopy (SEM) examinations, the presence of boron promoted grain growth and agglomeration in the β-SrTa2O6 grains, while the increased boron concentration led to grain elongation in addition to grain growth in the BaTa2O6 grains. The dielectric results for the β-SrTa2O6:xEu3+ and β-SrTa2O6:xEu3+, yB3+ series showed that increased Eu3+ caused a decrease in the dielectric constant (ε′) and dielectric loss (tan δ), whereas the increasing B3+ presence for the BaTa2O6:xEu3+, yB3+ series led to an increase in the dielectric constant and a decrease in dielectric loss. The increase in tetragonality for BaTa2O6:xEu3+, yB3+ ceramics was correlated with a higher ferroelectric Curie temperature. [ABSTRACT FROM AUTHOR]

[Display omitted] The poor stability and slow lithium ion (Li+) transfer kinetics of solid electrolyte interphase (SEI) pose significant challenges to lithium (Li) metal batteries. Although various SEI-related strategies have been developed, the Li+ transport properties and uniform Li deposition still require substantial improvement for fast-charging applications. Herein, we introduce a dielectric, single-ion-conductive artificial SEI (DS-SEI) composed of lithiated Nafion and BaTiO 3 (BTO) nanoceramics to address these issues. The lithiated Nafion stabilizes the Li anode with its elastic F-rich components and facilitates fast, single Li+ conduction through its anion-anchored structure. The high-dielectric BTO dynamically homogenizes the electric field (E-field) to promote uniform Li deposition, synergistically enhancing intrinsic single Li+ conductivity and Li+ desolvation/diffusion kinetics, thereby enabling fast charging of the Li anode. Consequently, the DS-SEI protected Li anode can cycle over 6800 h in a Li||Li cell at 10 mA cm−2/5 mAh cm−2, over 400 cycles in a 2.75 mAh cm−2 Li||LiFePO 4 cell at 1C, with 83.0 % capacity retention at 6C (16.5 mA cm−2), and maintain stable cycling in a 5.62 mAh cm−2 Li||Li 6 PS 5 Cl|| LiNi 0.8 Co 0.1 Mn 0.1 O 2 all solid-state cell. Our findings provide insights into the interfacial regulation of Li anode, paving the way for fast-charging Li metal batteries. [ABSTRACT FROM AUTHOR]

In this study, polyvinyl alcohol (PVA)/Na-Bentonite composites were prepared. In the preparation of composites, a maximum of 13% polymer by mass was loaded into the clay. Structural properties of composites prepared by solution mixing technique were examined using X-ray fluorescence spectrometry (XRF), Fourier Transform infrared spectrometry (FTIR) and X-ray diffraction (XRD) techniques. Dielectric properties were determined with the help of Dielectric spectroscopy (DS). From the XRF study, it was understood that the origin of the clay was Calcium bentonite (Ca-Bentonite) provided from the Asbro-Horio reservoir on the island of Milos, Greece, and that the Supplier (Imerys-Türkiye) converted the clay into NaBentonite through the sodium enrichment process. From XRD and FTIR measurements, it was observed that PVA interacted with the Na-Bentonite surface instead of being located between the Na-Bentonite galleries. This interaction between polymer and clay limited both the segmental movement of the polymer chains and the orientation of the hydroxyl groups on the clay surface. The electrode polarization effect is significantly reduced in composites with low PVA content. In low-dimensional capacitive systems, the use of materials with low dielectric constant comes to the fore to prevent resistance-capacitance (RC delay) delay. The important factor affecting the dielectric constant in the low frequency region is the electrode polarization effect. Thus, the low electrode polarization effect composites produced in this study can serve this purpose [ABSTRACT FROM AUTHOR]

Abstract The non-conventional manufacturing technologies are notorious when it comes to productivity and processing time in production-related industries. However, the aerospace and other high-end sectors enjoy another quality matrix of these processes and compromise on the processing time. For instance, the machinability of hard-to-cut materials such as Ti6Al4V aerospace alloy for micro-impressions is challenging and commonly carried out through non-conventional processes. Among these processes, the electric discharge machining (EDM) is famous for machining Ti6Al4V. In the current study, the EDM process is enhanced through modified dielectrics such as kerosene with non-ionic liquids (span 20, 60, and 80) and cryogenically treated tool electrodes (aluminum and graphite), and is compared to the conventional kerosene-based process. A three-phase experimental campaign is deployed to explore parametric effects including modified dielectric conditions (non-ionic liquid type and concentration), tool material, and machine parameter pulse ON:OFF time. A total of 60 experiments (54 modified dielectrics and 6 as baseline) were performed to explore process physics. The statistical analyses show that the unmodified process (kerosene dielectric-based) results in the least favorable results 0.58 mm3/min against cryo-graphite and 1.2 mm3/min against cryo-aluminum electrodes. However, the modified dielectrics outperform and improve process dynamics by altering dielectric conditions through hydrophilic-lipophilic balance. Surface morphological analysis shows significantly shallow craters on the machined surface showing evidence of effective flushing through a modified dielectric (S-20) as compared to a kerosene-based dielectric. A thorough microscopical, statistical, and scanning electron-based analysis is carried out to explain the process and correlate significant improvements.

The multiferroics with remarkable magnetoelectric (ME) coupling and technological application have drawn significant attention. Here, we report a chemical doping tunable effect on the magnetic, ferroelectric, and dielectric properties in type-II multiferroic Gd 2 BaCuO 5. The magnetic measurement results show that a long-range antiferromagnetic ordering forms at the Néel temperature (T N1) of ∼12.1 K, and a second magnetization anomaly occurs at a lock-in transition temperature (T N2) of ∼6.4 K. Sharp peaks in the pyroelectric and dielectric curves are observed at the magnetic transition temperatures, indicating intrinsic coupling between magnetic and ferroelectric orderings. The doping of Zn2+ results in a gradual enhancement of magnetization due to the increase of uncompensated spins, and large magnetodielectric (MD) coupling parameter up to ∼7.65 % is obtained in Gd 2 BaCu 0.7 Zn 0.3 O 5 because of strong spin-phonon coupling. The ferroelectric property is weakened in Zn2+ doped samples, suggesting the critical role of the 4 f -3 d magnetic interactions in determining the ME coupling effect. Moreover, an effective manipulation of electric field on magnetization is observed in Gd 2 BaCuO 5. This work helps understand the importance of 4 f -3 d magnetic interactions in inducing ferroelectricity and explore the ME and MD coupling effects with multiple magnetic orderings. [ABSTRACT FROM AUTHOR]

Multiferroic composites of sol-gel synthesized Sodium Bismuth Titanate (Na 0.5 Bi 0.5 TiO 3) and Co–Ti substituted Barium Hexaferrite (BaFe 12-2x Co x Ti x O 19 ; x = 0.0, 0.5, 1.0, 1.5 and 2.0) in the ratio 3:1 was synthesized through ceramic route. Successful formation of R3c rhombohedral and P63 / mmc hexagonal phases corresponding to Na 0.5 Bi 0.5 TiO 3 and BaFe 12-2x Co x Ti x O 19 respectively was confirmed from the XRD and Rietveld refinement pattern. The frequency and temperature dependence of dielectric constant and loss of the composite systems exhibited typical dispersion behaviour which could be understood using the Maxwell-Wagner model. Substituted samples showed enhanced dielectric behaviour where dielectric constant was observed to increase while loss tangent decreased. Using the Universal Jonscher's Power law (JPL), conductivition mechanisms of the composite systems were studied from the ac conductivity behaviour which revealed that the x = 0.0 sample followed Non-overlapping Small Polaron Tunnelling (NSPT) model while the remaining samples followed the Correlated Barrier Hopping (CBH) model. The complex impedance and Nyquist plot analysis showed the enhancement of resistive property in the x ≠ 0 systems. Magnetic hysteresis loop measurements were conducted, and the associated parameters were determined with the assistance of the Law of Approach to Saturation (LAS). Favourable reduction in the magnetic anisotropy was observed indicating the disturbance of magnetic spin structure in the hexaferrite phase. The P-E loops established the novel room temperature multiferroic nature of the composite systems. Significant magnetoelectric coupling was detected at room temperature in all samples, with the x = 0.5 sample exhibiting the highest value of approximately 59.81 mV/cmOe. These desirable properties suggest that the composites may find future device applications as in magnetically tunable energy harvesting devices and self-powered magnetoelectric sensors in the future. [ABSTRACT FROM AUTHOR]

The crystallographic, microstructural, and dielectric properties of Sr 2.1 Na 0.8-x Ca x Nb 5-x Sn x O 15 (x = 0.00, 0.01, 0.05, 0.10) polycrystalline ceramics have been studied by X-ray diffraction, scanning electron microscopy, dielectric spectroscopy (DS) and impedance spectroscopy (IS). For x = 0.00, 0.05, and 0.10, samples are single phase with P 4 bm symmetry at room temperature with x = 0.01 showing a small quantity of secondary phase(s). All compositions show typical ceramic microstructures and d 50 grain sizes ranging from 5.1 to 26.6 μm. DS shows a clear trend in the high temperature ferroelectric-paraelectric transition with the Curie temperature, T 0 , decreasing from ∼ 160 to ∼ 110 °C, and an additional relaxation at approximately 120 °C with increasing CaSnO 3. IS reveals all samples have a homogeneous electrical microstructure with predominantly electronic conduction. The activation energy of conduction calculated from Arrhenius plots of the conductivity increases with CaSnO 3 content from 1.27 to 1.38 eV likely due to the expansion of the band gap. [ABSTRACT FROM AUTHOR]

Forsterite was synthesized with MgCO 3 and SiO 2 powders using a solid-state method at 1200–1300°C. The ceramic specimen with the highest forsterite phase content was sintered with the ZrO 2 sintering aid at mass fractions of 0.5, 1.0, and 1.5 wt% at 1400°C for 4 h. The dielectric constant and loss tangent were also measured via the waveguide method at 8–12 GHz. The formation of enstatite and cristobalite was minimized through precise synthesis temperature control. Phase measurement by the Rietveld method showed that specimen F28 contained more than 99.8% forsterite. It was found that ZrO 2 reduced the pore volume percent and increased the density even at low mass fractions. A liquid phase on the grain boundaries was demonstrated. The solid ceramic specimen F28-15Z showed a dielectric constant of 6.5 and high quality factor of 189000. [ABSTRACT FROM AUTHOR]