In ferroelectric ceramics, the grain size can influence both structure and properties. In this work, three AgNbO3 ceramics, with average grain sizes ranging from 230 nm to 2.7 mu m, were fabricated. Rietveld refinement was performed for their structures using the polar space group Pb2(1)m, consistent with their ferrielectric nature, as evidenced by the E-1 peaks observed in current-electric field (I-E) loops. As the grain size increases, the ferrielectric distortion b/a increases, while the cell volume V decreases. All transition temperatures, between the M-1-M-2a, M-2a-M-3, and M-3-O phases, shift to lower values, and the permittivity peaks associated with these transitions become broader with decreasing grain size. This can be attributed to small and dynamic polar structures with a wide size distribution in fine-grained ceramics, and relatively large sized polar structures with clearer domain walls in coarse-grained ceramics, as supported by transmission electron microscopy results. Under high electric field, double hysteresis loops indicative of antiferroelectric behavior were observed. With decreasing grain size, the field-induced polarization decreases, and both forward and backward reversal fields (E-F and E-B) increase, which can be attributed to the increased restriction from grain boundaries.

Materials for energy storage and production that are sustainable in nature are highly significant in today’s world. In the current study, a facile, cost-effective, and phytogenically induced fabrication of CuOSbOZrO2 ternary nanocomposite is reported using Amaranthus viridis L. leaf extract as a natural stabilizer. The morphological properties were examined through SEM, XRD, and EDX analysis, and thus, it has been found that the ternary oxides have formed. The prepared AV.LA-CuOSbOZrO2 nanocomposite material was impregnated on Nickel Foam to observe its efficiency in supercapacitor and electrocatalysis applications. When tested as a supercapacitor electrode, it yielded a high specific capacitance value of 456 F/g at 2 mV/s and 365 F/g at 1 A/g in 3 M KOH electrolyte. Additionally, the AV.LA-CuOSbOZrO2-NF electrode presented impressive bifunctional catalytic performance in overall water electrolysis reactions, requiring only 210 mV and 360 mV overpotential for hydrogen evolution reaction and oxygen evolution reaction, respectively, to attain 10 mA/cm2 current density. Pertinent Tafel slopes were measured to be 113 mV/decade and 205 mV/decade for the HER and OER reactions, respectively. Durable performance was obtained through the test of 1,000 LSV cycles and 18 h of chronoamperometry measurements. Herein, we report for the first time a cost-effective approach towards fabrication of CuOSbOZrO2 electrode on commercial NFs.

In the current work, we have prepared novel Bi2O3-based nanomaterials for the application of energy storage supercapacitors and energy generation overall water splitting via a facile green synthesis route. Bi2O3 is hydrothermally doped by different concentrations of La2O3 ranging from 2.5% to 10% in the presence of phyto (bio) reducing and stabilizing agents to obtain phytochemicals incorporated La2O3 doped Bi2O3 as A.viridis [Bi2O3:La2O3] nanomaterials. All samples of synthesized materials are fully characterized by scanning electron microscopy, X-rays diffractometry, energy dispersive X-ray spectroscopy, and Fourier Transform Infrared Spectroscopy. A.viridis[Bi2O3:La2O3] nanomaterial-based Bi2O3:La2O3-NF electrode reveals higher specific capacitance of 890 F/g at 2 mV/s to 300 mV/s and 292 F/g at 1 A/g by cyclic voltammetry and galvanostatic chargedischarge respectively. Bi2O3:La2O3-NF expresses a higher energy density of 14 Wh/Kg with excellent rate stability. As a bifunctional electrocatalyst, Bi2O3:La2O3-NF reveals a lower overpotential of 133 mV with a Tafel slope value of 191 mV/dec for 10 mA/cm2 current density. Furthermore, Bi2O3:La2O3-NF electrocatalyst demonstrates excellent stability till the 1000 LSV cycle and superior durability till 20 h of chronoamperometry studies. Overall results of the study well demonstrated significant energy storage and generation.

ABSTRACT Magnesium‐ion batteries (MIBs) are a promising alternative to lithium‐ion technologies due to their inherent safety and potential for sustainable, large‐scale energy storage, yet their development remains hindered by the scarcity of high‐capacity cathode materials. In this study, we reveal a significant leap in performance in a structurally unique quasi‐1D pseudo‐layered NbS3 cathode for MIBs, achieved through electrochemical interlayer engineering. In operando and ex situ PXRD, SEM‐EDS, and XPS confirm the intercalation of 1‐butyl‐1‐methylpyrrolidinium (BMPyrr+) cations, which results in substantial expansion of the interlayer spacing. This expansion not only enhances magnesium ion diffusion but also activates the dual Nb4+/Nb3+ and S22−/S2− redox processes for access to abundant ion storage sites, as elucidated by ex situ XAS analysis. In addition, multiple coupled factors, including BMPyrr+‐enabled channel opening and electrochemically induced morphological reconfiguration (i.e., nanosizing/fragmentation) further promote pseudo capacitive behavior. Consequently, the expanded NbS3 electrode delivers a high reversible capacity of up to 200 mA h g−1 at 50 mA g−1, plus excellent cycling stability, significantly outperforming its unmodified counterpart. This work highlights NbS3 as a novel dual‐redox trichalcogenide cathode for MIBs and demonstrates the power of interlayer expansion in unlocking inherent redox reactions for improving performance in multivalent‐based energy storage systems.

High‐entropy oxides are attracting attention for catalysis, but there are relatively few detailed studies on their precise structure, hampering true detailed studies on fundamental properties affecting their activities. In addition, diffusion has been often characterized as generally slow in high‐entropy systems. Here, we determine the precise oxygen content and structure of the fluorite‐like high‐entropy oxide (La, Ce, Pr, Nd, Y)O1.68 and have identified a large oxygen storage capacity based on efficient Ce/Pr redox due to facile oxide diffusion pathways and suppression of sintering. The structure and composition were identified through a combined Rietveld refinement of X‐ray and neutron diffraction data, and the oxidation state of Ce and Pr was investigated by high energy resolution fluorescence detected–X‐ray absorption near edge spectra (HERFD–XANES). (La, Ce, Pr, Nd, Y)O1.68 utilizes the full redox range of Ce/Pr, resulting in a high oxygen storage cumulative capacity despite the lower content of Ce/Pr compared to other well‐known ceria derivatives. Diffusion pathway analysis by bond valence site energy mapping shows decreased barriers for oxide anion diffusion through the bulk, also benefiting redox reactions. The high‐entropy nature also suppresses sintering, resulting in better cycling performance. This results in a higher performance as a methane oxidation catalyst support. We also investigate its use as a NOx reduction catalyst support.

Incommensurate structural modulation is a defining yet poorly understood feature of several functional solids, particularly regarding its impact on defect dynamics in fast-ion conductors. Here, using the model oxide-ion conductor Bi2V0.9Cu0.1O5.35 (BICUVOX.10), we achieve the first full determination of a (3 + 2)D incommensurately modulated structure in the well-known gamma-type BIMEVOX family. Combined single-crystal and powder X-ray diffraction, neutron total scattering with reverse Monte Carlo modelling, and ab initio molecular dynamics (AIMD) reveal that the gamma '-phase exhibits short-range oxygen-vacancy ordering that intrinsically causes its modulation behavior. Upon heating, this vacancy ordering transforms into the dynamically disordered gamma-phase, establishing the structural origin of fast-ion conduction. The modulation waves strongly constrain oxygen motion within the vanadate layers, elevating the activation energy, while the coupled apical-equatorial positional modulations generate versatile V/Cu coordination geometries and a zig-zag oxide-ion diffusion network. In addition, Cu atoms were found to act as local vacancy traps. These findings identify vacancy-driven modulation as the mechanism governing the reversible gamma ' <-> gamma transition and establish a general framework linking incommensurate structural modulation, defect organization, and ionic transport in complex solid-state conductors.

Conventional methods for hydrating bulk ceramic samples at relatively low pressures (<5 atm of water steam) often fail to achieve significant hydration because of kinetic barriers and mechanical failures, the latter primarily due to inhomogeneous lattice expansion accompanying hydration. We propose a small, high-pressure chamber that can reach tens of atm of steam pressure without the necessity of operating a high-pressure/high temperature autoclave or pressure vessel. The chamber takes advantage of the dehydration of CoSO47H(2)O powder to stabilize water partial pressure up to 100 atm. This facilitates effective hydration at moderate temperatures, producing crack free pellets under reproducible conditions. Using La0.45Ce0.55O1.775 ceramics (LCO45) as a test case, we demonstrate that hydration in the chamber with p(H20) approximate to 56 atm produces at least ten times more water incorporation than hydration with 1 atm steam (38.5 % vs 3.7 % of oxygen vacancies filled) at the same temperature, 673 K, while requiring approximately one-tenth of the time (5 h vs 48 h). X-ray powder diffraction reveals an expansion of 0.43 % in the fluorite lattice parameter of LCO45 ceramics hydrated in the chamber. Chamber hydration increased conductivity in the temperature range 383-463 K by ca. two orders of magnitude compared to the dry pellet, the increase attributable to proton conductivity. The hydration protocol described below does not allow independent setting of temperature and pressure; however, due to its simplicity and economic accessibility, it may provide a viable method for achieving a high degree of hydration in ceramic samples while, at the same time, preserving their mechanical integrity.

Proton conductors are essential for a wide range of applications including solid oxide fuel cells, sensors and resistivity switches. However, commonly used proton-conducting materials such as Nafion, doped barium zirconate, and cesium dihydrogen phosphate suffer from significant limitations - including poor long-term stability and microfabrication compatibility. Recent work has shown that bulk La2Ce2O7 (LCO50) ceramics hydrate in moist environments and exhibit increased conductivity at temperatures below 473 K. In this work, we investigate the hydration behavior of magnetron-sputtered LCO50 thin films. We demonstrate that water can be incorporated into the crystal lattice, leading to an approximately fivefold increase at 363 K in the total conductivity of the as-deposited film. Extrapolating the exponential temperature dependence to room temperature, yields an approximately 103 fold conductivity enhancement, in agreement with values derived from XPS/CREM. To confirm that the total conductivity of the hydrated film is at least partially protonic, and to demonstrate that LCO50 can function as a mixed ion conductor, we demonstrate its use as the electrolyte in a layered tungsten oxide electrochromic device.

While various materials have been explored for the transducer of flexible ultrasound sensors, there remains a significant need for transducer materials that simultaneously achieve both high electromechanical coupling efficiency and mechanical robustness for skin-conformal ultrasound applications. In this study, we present a flexible ultrasound sensor based on novel erbium-doped Pb(Mg0.33Nb0.67)(x)Ti(1-x)O3 (PMNPT) piezo ceramics (x=0.30) , which exhibit an electromechanical coupling coefficient (k(t)) of 58.4%. Simple and cost-effective methods were explored to fabricate soft electronic circuits and to assemble the flexible ultrasound sensor. Acoustic testing further confirms a 6-dB one-way bandwidth of 27.8% at a center frequency of 6.04 MHz, ensuring high resolution. As a proof-of-concept, we demonstrate its capability to capture blood pressure (BP) waveforms directly from the brachial artery, correlating arterial diameter dynamics with localized blood-pressure variations. Additionally, the patch was used to accurately measure different blood-mimicking flow rates (BFRs) in a vessel-mimicking phantom. The novel Er-doped PMNPT ceramics specifically improve the electromechanical coupling coefficient and ultrasound signal bandwidth, which are critical for enhancing the performance of flexible systems intended for high-resolution vascular monitoring.

Ferroelectric oxides PbZr1-x Ti x O3 (PZT) with the ABO3 perovskite structure exhibit exceptional polarization responses near their morphotropic phase boundary (MPB), yet the chemical origin of this behavior remains unclear. Here, we show that, in a prototypical composition, 0.05Pb(Mn1/3Sb2/3)O3-0.95PbZr0.52Ti0.48O3, this origin arises from coupled effects of B-site chemical ordering and multi-ion displacement heterogeneity-related disordering. Pronounced anti-self-clustering of Zr and Ti forms a short-range chemical ordering driven by the mismatch between ionic Zr-O and more covalent Ti-O bonds, generating a soft-hard compatible BO6 network that reduces local stress, which facilitates polarization rotation and switching. Simultaneously, A-site, B-site, and oxygen ions display significant, directionally distinct off-center displacements, producing continuous local monoclinic polar states (MA-MB) with coplanar polarization vectors and nanoscale domains with mobile walls. These results show that PZT's extraordinary response emerges from a unity-of-opposites relationship that balances rigidity and flexibility through compatible bonding and multi-ion displacements, offering guidance for designing high-performance ferroelectrics.

Magnesium-lithium hybrid ion batteries (MLIBs) offer a promising energy storage technology that combines the safety and dendrite-free plating/stripping of Mg anodes with the rapid Li+-dominated diffusion in cathode materials. However, for electrodes that undergo significant volume/structural changes during cycling, conventional slurry-cast fabrication often leads to microstructural degradation, active material detachment, and consequently, poor cycling stability and rapid capacity fading. Here, we report a self-standing, carbon- and binder-free tantalum trisulfide (TaS3) nano fibrous (NF) film, synthesized via a facile one-step physical vapor transport reaction that addresses these challenges through mechanistic innovations. Mechanistic investigations reveal that the TaS3 NF electrode undergoes dual cationic (Ta5+/Ta3+) and anionic (S22-/S2-) redox reactions, accompanied by electrochemically induced phase transitions and in situ exfoliation. The dual redox couples provide a large number of Li+ ion storage sites, while the structural changes lead to fiber-level nanosizing, which in turn promotes fast (near) surface ion storage and pseudo capacitive behavior. Despite these significant transformations, the robust fibrous architecture retains structural integrity throughout prolonged cycling, as confirmed by in operando and ex situ characterization. This dual-redox, in situ exfoliation, and architecture-driven mechanism underpins the electrode's exceptional cycling stability and high rate capability. As a result, the TaS3 NF electrode achieves a high reversible capacity of 178.5 mA h g-1 at 50 mA g-1, maintains 91.6% of reversible capacity after 100 cycles, and delivers 144.4 and 119.0 mA h g-1 at 500 and 1000 mA g-1, respectively, surpassing those of slurry-cast bulk TaS3 controls. Furthermore, the maintenance of a flexible film structure after extended cycling suggests potential applicability in next-generation wearable and structurally adaptive energy storage systems. These findings highlight the potential of self-standing, carbon- and binder-free film electrodes in advancing the cycling stability, energy density, and design versatility of MLIB systems and beyond.

Dopant size is known to influence oxygen vacancy-mediated conduction pathways and ionic conductivity in doped ceria, yet the underlying atomic-scale mechanisms remain unclear. Here, we combine neutron total scattering and large-scale atomistic simulations to analyze the local defect structures of two representative doped ceria systems: Ce0.8Gd0.2O1.9 (GDC) and Ce0.8Nd0.2O1.9 (NDC). The local structure of GDC, a commercially used ion conductor, is investigated for the first time using neutron total scattering on 160Gd-enriched samples. GDC exhibits fewer defect clusters, with vacancy pairs preferentially aligned along ⟨111⟩ and ⟨110⟩ directions while disfavoring ⟨100⟩ direction within the cubic fluorite structure. The Gd-Gd interactions in GDC help destabilize ⟨100⟩ ordering, promoting a more open defect network that supports efficient oxygen-ion transport. Unlike Gd3+ (1.053 Å in 8-fold coordination with oxygen), the slightly larger dopant Nd3+ (1.109 Å) in NDC promotes a more compact defect configuration, characterized by increased defect clustering and stabilized ⟨100⟩ vacancy alignment due to dominant Nd-vacancy interactions, substantially reducing ionic conductivity. Gd3+ provides an optimal balance of lattice expansion and preserving favorable defect structure for ion transport. These findings provide a mechanistic understanding of dopant-size controlled conduction pathways in lanthanide-doped ceria and fundamentally contribute to the understanding of charge transport by ions, electrons, and protons in next-generation conducting materials.

Lead-free antiferroelectric (AFE) ceramics based on AgNbO3 represent attractive materials for energy storage applications but are limited by their recoverable energy density (Wrec). Here Bi3+/Ca(2+ )A-site modification of AgNbO3 ceramics has yielded a particularly high Wrec of 4.4 J cm(-3) and a superhigh recoverable energy storage intensity (rho) of 21.46 x 10(-3) J kV(-1) cm(-2) at 205 kV cm(-1), the latter being the highest known value obtained at such a relatively low field for a lead-free ceramic. The modification shifts the dipole freezing temperature, Tf, to below room temperature, enhancing the room temperature stability of the AFE structure. The high Wrec is attributed to the enhancement of the maximum field-induced dielectric displacement and improved forward (EF) and backward (EB) fields. The work has also allowed for an examination of the poorly understood +/- EU current peaks evident in current-electric field loops of AgNbO3 -based ceramics, which is proposed to be related to a field-induced AFE to ferroelectric (FE) phase transition in the M-1 or M-2a phases and is absent in the M-2b phase due to increased stability of the AFE phase. The exceptional performance of Bi3+/Ca2+ modified AgNbO3 ceramics is promising for potential use in ceramic capacitors for high pulsed power applications.

Naphthalene diimide (NDI) based molecules are soft organic functional materials investigated for their n-type semiconducting properties and, recently, for their coupled electronic and ionic transport properties. Such qualities make them potential candidates as mixed ionic-electronic conductors (OMIECs) for electrochemical energy storage devices and bioelectronic sensors. A key aspect is the rationalization of their solid-state structure and morphology, which ultimately controls their transport properties. Here, we introduce two newly synthesized NDIs, namely, NDI-TEG, functionalised with linear triethylene glycol side chains, and NDI-crown, with 15-crown-5 rings. Their bulk structural properties, investigated via experimental characterization and state-of-the-art molecular dynamics (MD) simulations, are compared with those of the parental species NDI-C10, featuring symmetrical n-decyl side chains. Our MD simulations reproduce remarkably well the experimental crystal structures of NDI-C10 and NDI-TEG. At the same time, we compute ex novo the amorphous morphology of NDI-crown, by simulating the experimental film casting conditions. Structural order parameters and correlation functions allow us to gain detailed atomistic insights into both short- and long-range order, as well as to investigate the thermal disorder effects, highlighting the role of the functional side groups. Our study establishes a validated computational ground for modelling NDIs in condensed solid phases, benchmarking the procedure with respect to experimental XRD data, and extending it to amorphous films, thus paving the way for an in-depth understanding of the structure-property functions of small molecule n-type semiconductors.

Single-phase multiferroics (MFs) exhibiting ferroelectricity and ferromagnetism and the strong magnetoelectric (ME) coupling effect at room temperature are seen as key to the development of the next-generation of spintronic devices, multi-state memories, logic devices and sensors. Herein, the single-tetragonal phase (1–x) (Sr0·3Bi0·35Na0·329Li0.021)TiO3-xBiFeO3 (x = 0.2 or 0.4) system was designed to study the intrinsic ME coupling effect at room temperature and high frequencies. The polarization arises from the cooperative displacement of both Fe3+ and Ti4+ relative to the oxygen sublattice in the tetragonally distorted perovskite structure, and the magnetization stems from indirect exchange magnetic interaction between adjacent iron ions. A switchable voltage-controlled magnetization was confirmed by a change of the coercive magnetic field, Hc, and remnant magnetization, Mr, in the x = 0.4 component subjected to an external electric field at room temperature and was possibly attributed to a strain-mediated ME coupling effect. In addition, resonance behaviours of the complex magnetic permeability and complex dielectric permittivity in the GHz band indicate that this ME effect is intrinsic in nature and could broaden the applications of multiferroics to devices operating at microwave frequencies.

Ceramics based on the perovskite Na0.5Bi0.5TiO3 (NBT) have attracted attention due to their ferroelectric properties, high Curie temperature ( similar to 325 degrees C) and large remnant polarization similar to 38 x 10(-6) Ccm(-2)). Interestingly, NBT also shows high oxide-ion conductivity when the Na:Bi mol ratio is above unity, but conductivity is significantly lower when the ratio is at or below this value. Despite significant scientific efforts, this phenomenon lacks a robust explanation. Here we combine experimental measurements with state-of-the-art Density Functional Theory, using the Strongly Constrained and Appropriately Normed functional (SCAN) together with the Dudarev formulation of the on-site Coulombic interactions to model the oxide-ion dynamics in NBT. The dynamic properties of mobile ions are correlated with subtle changes in the electronic structure, in the form of emerging polarons. These are observed to be positioned in the vicinity of space-separated oxide-ion vacancies when Na:Bi < 1, but when Na:Bi > 1 only half the vacancies are adjacent to polarons and are mutually attracted, leading to the formation of vacancy clusters that become mobility centers for diffusing ions.

Current study introduces first report on the sustainable synthesis of GeO2 - ZnO nano-hetero-system copulated with the microwave treatment. GeO2 - ZnO has been effectively tuned for the band gap causing an alleviation from 4.89 to 2.89 eV upon the nanocomposite formation. With the hexagonal phase, GeO2 - ZnO possessed an average crystallite size of the 62.11 nm. These particles existed as nano-rossettes with the uniform upward projection. The catalytic performance of the synthesized material was more inclined towards pure hydrogen generation with the lower overpotential (eta HER) and Tafel slopes i.e. 128 mV and 121.9 mV dec- 1. GeO2 - ZnO nano-rossettes bedecked electrode remained unscathed for a prolonged duration of the 1500 min and demonstrated commendable charge storage with the unit capacity of 384 mAH g- 1. As a passivation layer in perovskite solar cells, these nanomaterials improved efficiency up to 15 % by prevention of the charge aggregation.

Transparent ferroelectrics with high linear electro-optic (EO) coefficients are critical for advanced electro-optical devices. However, achieving optical transparency in ferroelectric ceramics remains challenging due to visible light scattering caused by defects such as domain walls, grain boundaries, and pores. Here, we report the successful fabrication of transparent ferroelectric ceramics through innovative chemical composition design and an advanced two-step sintering process in the La-doped Pb(Mg1/3Nb2/3)O3-PbTiO3 system. The optical transparency, which is near the theoretical upper limit, can be attributed to the wide band gap and the minimization of light scattering of defects. By minimizing porosity and engineering grain/domain sizes to differ significantly from the wavelengths of visible light, we suppress scattering, achieving optical transparency near the theoretical upper limit. Strikingly, these ceramics exhibit an ultrahigh linear EO coefficient of ∼1417 pm/V, over 65 times greater than that of LiNbO3 single crystals, the current industry standard. We attribute this exceptional performance to dynamic atomistic polar structures within switchable, thermally stable domains, which enhance electronic polarization sensitivity. This mechanism is corroborated by dielectric spectroscopy, high-resolution transmission electron microscopy and simulation. Our findings offer insights into the design of cost-effective transparent materials with exceptional EO properties, paving the way for next-generation electro-optical devices.