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This research explores the intricacies of oxygen exchange kinetics in Pr4Ni3O10+δ (PNO), aiming to assess its potential as a viable cathode material for solid oxide fuel cell applications. Utilizing a multifaceted approach, advanced techniques such as electrical conductivity relaxation, pulse isotopic exchange, and oxygen permeation are employed. A comparative analysis with other promising cathode materials, specifically La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF6428), reveals PNO superior performance. At 650 °C, PNO exhibits a chemical diffusion exchange coefficient, Dchem, and surface exchange coefficient, kchem, that are an order of magnitude higher than those of LSCF6428. Long-term stability assessment through 1000-h electrical conductivity relaxation testing at 700 °C confirms PNO consistent performance. Oxygen permeation studies reveal an inverse correlation between membrane thickness and the permeation rate. Notably, PNO demonstrates an impressive two-fold higher oxygen flux compared to LSCF6428. Furthermore, PNO maintains stable oxygen permeation over 1000 h at 700 °C, contrasting with an observed 11% degradation in LSCF6428. X-ray diffraction and scanning electron microscopy analyses corroborate PNO stability, while secondary phase formation observed in LSCF6428 contributes to its degradation. The pulse isotopic exchange measurements conducted on the fractionated powder of PNO within the temperature range of 350–450 °C provide valuable insights into the surface exchange mechanism. These measurements reveal that at the highest oxygen partial pressure (pO2) values covered by the experiments, the relative rates of dissociative adsorption, ℜads, and oxygen incorporation, ℜinc, engage in competitive oxygen exchange dynamics. Conversely, at lower pO2 values, oxygen exchange is predominantly limited by ℜads. [ABSTRACT FROM AUTHOR]

This study thoroughly examines the structural, mechanical, thermal, electronic, optical, and thermoelectric properties of RhMnZ (Z = Si, Ge) half-Heusler compounds, which feature 18 valence electrons. Using density functional theory (DFT) within the WIEN2k computational framework, the ground-state properties of these compounds were determined to establish a foundational understanding of their physical characteristics. To further assess their thermoelectric potential, the Boltzmann transport equation was applied with the constant relaxation time approximation, allowing for precise calculations of thermal and electrical conductivity. Results indicate that the lattice constants of RhMnSi and RhMnGe span from 5.6394 Å to 5.7447 Å, highlighting consistent crystalline structures that lack band gaps, confirming their metallic nature. Detailed elastic and thermodynamic evaluations demonstrate that these compounds are mechanically stable, displaying ductile and anisotropic behavior. The study further reveals that thermal properties, including specific heat and entropy, tend to increase with the atomic number of Z, suggesting that RhMnGe may have a slightly higher heat capacity compared to RhMnSi. For thermal conductivity estimation, Slack's model was employed, indicating that these compounds possess high lattice thermal conductivity—a crucial factor for thermoelectric materials. The substantial figure of merit (ZT) observed in these compounds, especially at elevated temperatures, points to their potential efficiency in thermoelectric applications. The combination of high thermal conductivity, favorable mechanical stability, and robust thermoelectric properties identifies RhMnZ compounds as promising candidates for use in energy conversion technologies, particularly where efficient heat-to-electricity conversion is needed. This study thus lays the groundwork for future applications of RhMnSi and RhMnGe in thermoelectric devices. [ABSTRACT FROM AUTHOR]

In this manuscript, perovskite oxide LaCoO3/LaMnO3/LaCoO3 (LLL) trilayers and the single-layer LaMnO3 (LMO) and LaCoO3 (LCO) films are epitaxially grown on (001)-oriented SrTiO3 substrates by polymer-assisted deposition combining with heat treating in Ar, air, and O2 atmospheres, respectively. The crystal structure and magnetic properties are investigated. It is found that the responses of LMO and LCO films to oxygen content are different, and the magnetic property of LMO is more sensitivity to oxygen content than that of LCO. The oxygen content can directly affect the structure and magnetic properties of LMO and LCO layers, which, in turn, modulate the interfacial magnetic properties of the LLL trilayers through interlayer coupling. By comparison with the magnetic properties of the single-layer films, an abnormal ferromagnetic (FM) transition is found in the LLL trilayers at around 216 K, besides two known FM transitions corresponding to those in the LCO and LMO layers, respectively. It is suggested that the abnormal FM transition is attributed to Mn4+–O–Co2+ FM super-exchange interaction, which is induced by the charge transfer from Mn3+ to Co3+ ions and the interlayer coupling between the LMO and LCO layers. The interlayer coupling of the trilayers, including the interfacial coupling and the diffusion-induced inlayer coupling, dominates the interface properties, which are tuned by oxygen content-dependent charge transfer. The cooperative function of the orbital/charge structure and the interlayer coupling dominates the magnetic properties of the LLL trilayer under the tensile strain. These findings provide new avenues to regulate the electronic and magnetic states of perovskite oxide multilayers and another way to the development of multifunctional electronic devices. [ABSTRACT FROM AUTHOR]

Renewable energy storage using electrochemical storage devices is extensively used in various field applications. High-power density supercapacitors and high-energy density rechargeable batteries are some of the most effective devices, while lithium-ion batteries (LIBs) are the most common. Due to the scarcity of Li resources and serious safety concerns during the construction of LIBs, development of safer and cheaper technologies with high performance is warranted. Magnesium is one of the most abundant and replaceable elements on earth, and it is safe as it does not generate dendrite following cycling. However, the lack of suitable electrode materials remains a critical issue in developing electrochemical energy storage devices. 2D MXenes can be used to construct composites with different dimensions, owing to their suitable physicochemical properties and unique magnesium-ion adsorption structure. In this study, the construction strategies of MXene in different dimensions, including its physicochemical properties as an electrode material in magnesium ion energy storage devices are reviewed. Research advancements of MXene and MXene-based composites in various kinds of magnesium-ion storage devices are also analyzed to understand its energy storage mechanisms. Finally, current opportunities, challenges, and future prospects are also briefly discussed to provide crucial information for future research., (© 2023 Wiley-VCH GmbH.)

In this study, we investigate the effect of mixed surface terminations (F, O, OH) on the properties of M2C MXenes (M = Sc, Ti, V). We explore how different compositions and patterns of terminal groups affect the stability and electronic properties of these 2D materials. The bond dissociation energies and cohesion energies show a clear preference for F-terminations in Sc2C, while Ti- and V-based MXenes prefer O-terminations. Our study is the first to demonstrate that terminal groups on opposite sides of the MXene have little to no influence on each other's electronic structure, allowing for independent chemical environments on each side. In a first of its kind investigation semiconducting forms of studied MXenes (Sc2CF2, Sc2C(OH)2 and Ti2CO2) showed very high sensitivity to conduction-inducing terminations (O, O, and F, respectively) with even minuscule amounts (≈1%) causing the materials to become conductive. This high sensitivity of the band gap to surface terminations may offer an explanation for the challenges in synthesizing semiconducting forms of MXenes. [ABSTRACT FROM AUTHOR]

Buchdahl star is the most compact object without an event horizon and is an excellent candidate for a black hole mimicker. Unlike black holes, rotating Buchdahl star can be over-extremal with respect to the black hole, sustaining a larger spin. We show that it can also develop an ergosphere above the threshold spin β > 1 / 2 , which allows extraction of its rotational energy. Electromagnetic field around Buchdahl star is also expected to differ from that of black hole in both strength and topology. In this paper, we explore the energetics of Buchdahl star focusing on the magnetic Penrose process in the two magnetic field configurations, i.e., uniform and dipole. Below the threshold spin, Buchdahl star is expected to be quiet, while above the threshold it can be much more efficient than the black hole if a dipolar magnetic field is developed on its surface. [ABSTRACT FROM AUTHOR]

The oxygen evolution reaction (OER) is a key reaction in the production of green hydrogen by water electrolysis. In alkaline media, the current state of the art catalysts used for the OER are based on non-noble metal oxides. However, despite their huge potential as OER catalysts, these materials exhibit various disadvantages including lack of stability and conductivity that hinder the wide-spread utilization of these materials in alkaline electrolyzer devices. This study highlights the innovative chemical functionalization of a mixed copper cobalt hydroxide with the V2CTx MXene to enhance the OER efficiency, addressing the need for effective electrocatalytic interfaces for sustainable hydrogen production. The herein synthesized CuCo@V2CTx electrocatalysts demonstrate remarkable activity, outperforming the pure CuCo catalysts for the OER and moreover show increased efficiency after 12 hours of continuous operation. This strategic integration improved the water oxidation performance of the pure oxide material by improving the composite's hydrophilicity, charge transfer properties and ability to hinder Cu leaching. The materials were characterized using an array of materials characterization techniques to help decipher both structure of the composite materials after synthesis and to elucidate the reasoning for the OER enhancement for the composites. This work demonstrates the significant potential of TMO-based nanomaterials combined with V2CTx for advanced innovative electrocatalytic interfaces in energy conversion applications. [ABSTRACT FROM AUTHOR]

The present paper provides interesting measurements and methodologies to investigate the key factors controlling the electrical response of perovskite systems. The studied system was successfully prepared using a solid-state route. The chemical analysis and the X-ray diffraction results confirm the formation of the desired perovskite phase. As a result, the DC-resistivity analysis shows that the transport properties are governed by hopping mechanisms above the transition temperature. In this case, thermal agitation allows the charge-carriers to hop across the insulating barrier in the form of grain boundaries. Then, the dominance of the grain boundary contribution is proved. AC-resistivity spectra are investigated in terms of numerous power laws (UDR, SPL and NCL). Accordingly, the decrease in the resistivity values at high frequencies is explained through hopping and tunneling processes. Indeed, it is proved that the electrical transport phenomena are governed by QMT and CBH models. The coexistence of direct (C–C) and indirect (C–A–C) interactions explains the multi-behavior of the AC-resistivity. The scaling representation displays a single muster curve describing the universal dynamic response (UDR). Thus, it reveals the universality of the electrical resistivity of the system. However, the double Schottky barrier model is used to explain the grain boundary effects. A critical frequency "νc" is detected under temperature and DC-bias voltage effects. These observations disclose, in a different way, the separate contributions of the electro-active regions of the sample in the conduction phenomenon. [ABSTRACT FROM AUTHOR]

Oxygen stoichiometry plays a vital role in determining the physical properties of transition metal oxides (TMOs) and their suitability for high-temperature thermoelectric applications. In the present study, oxygen-deficient BaBixCo1–xO3–δ (0 ≤ x ≤ 0.2) perovskite samples were synthesized using the sol-gel method. Structural analysis revealed the formation of oxygen-deficient phases with hexagonal structures. Morphological analysis showed significant changes in the size and interlayer growth of these phases with various levels of bismuth (Bi) substitution. The high thermal stability of the samples was confirmed by TGA. The binding state and composition of the samples were analysed by XPS. Thermoelectric studies were performed, and the results indicated that the electrical resistivity (ρ) decreased with temperature, indicating the semiconducting behavior of the samples. The Seebeck coefficient (S) increased for the samples with higher Bi content due to energy filtering effect. The sample with x value of 0.1 shows a high-power factor of 0.001 µWK− 2m– 1 at 600 K compared to other samples. The experimental findings demonstrated that the oxygen deficient BaBixCo1–xO3 – δ perovskite material exhibited high thermoelectric performance compared to the sample with mixed phase. Furthermore, Bi substitution was found to be a promising strategy for enhancing the thermoelectric performance, with specific compositions showing great potential for high-temperature thermoelectric applications. [ABSTRACT FROM AUTHOR]

Electronic transport in transition metal spinel oxides is associated with small polaron hopping, either nearest-neighbor, resulting in Arrhenius activated conductivity, or variable energy, leading to a sub-Arrhenius relationship, with the conductivity logarithm being a convex function of inverse temperature. For the case of manganese spinel oxides alloyed with zinc and nickel, instances of super-Arrhenius behavior are measured, with the conductivity logarithm functional dependence on temperature deviating quadratically. Here, we study the transport in Zn0.5NixMn2.5−xO4 ternary oxide pellets, as a function of Ni content in the range 0 ≤ x ≤ 1.25, in combination with structural characterization and theoretical investigations of their electronic and structural properties using density functional theory. The coexistence of cubic spinel and tetragonal Hausmannite structures is revealed along with the presence of various magnetic conformations that are metastable at room temperature. For systems where metastable structures exist, having similar formation energy but different electronic structures, conductivity is a non-trivial function of temperature. Considering nearest-neighbor polaron transfer in such an energetically inhomogeneous landscape, a new hopping mechanism model is proposed which consistently describes the temperature dependence of conductivity in this ternary alloy spinel oxide system. Understanding the underlying physical transport mechanism is vital for sensor, electrochemical, and catalytic applications. [ABSTRACT FROM AUTHOR]

Ytterbium silicide-based thermoelectric materials have attracted attention because they exhibit large power factors owing to large absolute values of their Seebeck coefficient as well as high electrical conductivity. Here, we demonstrate that, in the Yb(Si1−xGex)2 system, by controlling the valence fluctuation, we combine two phenomena, namely, the Kondo effect and suppression of the spin fluctuation. This leads to a large density of states and the suppression of the spin fluctuation of the 4f electrons, thereby resulting in a high Seebeck coefficient with extremely low resistivity. Consequently, Yb(Si0.5Ge0.5)2 exhibits a high-power factor of 8.4 mW K−2 m−1, which makes energy harvesting from a cold source a practical possibility. [ABSTRACT FROM AUTHOR]

Two-dimentional (2D) Ti 3 C 2 T x MXene has attracted significant attention in non-lithium-ion batteries due to its excellent electrical conductivity, high volumetric capacity, and ability to accommodate intercalants. Rechargeable magnesium batteries with Mg metal anodes are noted for their high theoretical energy density, potential safety, earth abundance, dendrite-free Mg 2+ plating/stripping mechanism on the anode side, and low cost. Nevertheless, owing to the large polarity of divalent Mg 2+ ions, the insertion of Mg 2+ into the MXene layers suffers from sluggish kinetics, limiting the performance for storage of Mg 2+ ions. Herein, a simple self-assembly strategy is demonstrated to achieve high magnesium ion storage capability with pillar-structured Ti 3 C 2 T x MXene by intercalating a hyperbranched polyethylene ionomer containing quaternary ammonium ions. The ionomer intercalation/modification leads to the expansion of interlayer spacing of the MXene and, meanwhile, improves its affinity to low-polarity THF-based electrolyte. The delaminated ionomer-modified MXene shows significantly improved electrochemical performance as a cathode material for Mg batteries. It shows a promising cycling stability with a capacity retention of 86% after 400 cycles at 200 mA g -1 , as well as outstanding high-rate performance with a capacity of 110 mAh g -1 retained at 1,000 mA g -1 relative to 213 mAh g -1 at 20 mA g -1 ., (© 2024 Wiley‐VCH GmbH.)

Solid oxide fuel cells (SOFCs) are considered as advanced energy conversion technologies due to the high efficiency, fuel flexibility, and all-solid structure. Nevertheless, their widespread applications are strongly hindered by the high operational temperatures, limited material selection choices, inferior long-term stability, and relatively high costs. Therefore, reducing operational temperatures of SOFCs to intermediate-temperature (IT, 500-800 °C) range can remarkably promote the practical applications by enabling the use of low-cost materials and enhancing the cell stability. Nevertheless, the conventional cathodes for high-temperature SOFCs display inferior electrocatalytic activity for oxygen reduction reaction (ORR) at reduced temperatures. Barium cobaltite (BaCoO 3-δ )-based perovskite oxides are regarded as promising cathodes for IT-SOFCs because of the high free lattice volume and large oxygen vacancy content. However, BaCoO 3-δ -based perovskite oxides suffer from poor structural stability, inferior thermal compatibility, and insufficient ionic conductivity. Herein, an in-time review about the recent advances in BaCoO 3-δ -based cathodes for IT-SOFCs is presented by emphasizing the material design strategies including functional/selectively doping, deficiency control, and (nano)composite construction to enhance the ORR activity/durability and thermal compatibility. Finally, the currently existed challenges and future research trends are presented. This review will provide valuable insights for the development of BaCoO 3-δ -based electrocatalysts for various energy conversion/storage technologies., (© 2024 Wiley‐VCH GmbH.)

Multivalent-ion batteries have garnered significant attention as promising alternatives to traditional lithium-ion batteries due to their higher charge density and potential for sustainable energy storage solutions. Nevertheless, the slow diffusion of multivalent ions is the primary issue with electrode materials for multivalent-ion batteries. In this review, the suitability of MXene-based materials for multivalent-ion batteries applications is explored, focusing onions such as magnesium (Mg 2+ ), aluminum (Al 3+ ), zinc (Zn 2+ ), and beyond. The unique structure of MXene offers large interlayer spacing and abundant surface functional groups that facilitates efficient ion intercalation and diffusion, making it an excellent candidate for multivalent-ion batteries electrodes with excellent specific capacity and power density. The latest advancements in MXene synthesis and engineering techniques to enhance its electrochemical performance have been summarized and discussed. With the versatility of MXenes and their ability to harness diverse multivalent ions, this review underscores the promising future of MXene-based materials in revolutionizing the landscape of multivalent-ion batteries., (© 2024 Wiley‐VCH GmbH.)

MXenes have garnered considerable attention as 2D functional materials. Their application in advanced applications is linked to synthetic approaches, terminal groups (＝O, –OH, and –F etc.) and multiple characteristics. Functionality and control over MXene terminations are important factors. MXenes exhibit a regular planar structure, conductivity, tuneable fabrication and structural modifications, as well as superior optical, thermal, and chemical properties. These exceptional characteristics grant MXenes and their derivatives distinction among 2D materials. MXenes have practical applications in energy conversion/storage, catalysis, sensing, water purification, drug delivery, and cancer treatments. Recent advances, with a primary focus on MXenes synthesis and terminations linked to their method of preparation, are the focus of this review. We offer potential solutions to the challenges faced by researchers during MXene synthesis. We describe the advantages, drawbacks, and mechanism associated with MXene fabrications and developments. Despite significant progress on MXene-oriented research, several challenges must be addressed before practical applications. [ABSTRACT FROM AUTHOR]

Thermoelectric generators are very attractive devices for waste heat energy harvesting as they transform a temperature difference into electrical power. However, commercially available generators show poor power density and limited operation temperatures. Research focuses on high‐temperature materials and innovative generator designs. Finding the optimal design for a given material system is challenging. Here, a theoretical framework is provided that allows appropriate generator design selection based on the particular material properties. For high‐temperature thermoelectric oxides, it can be clearly deduced that unileg multilayer generators have the highest potential for effective energy harvesting. Based on these considerations, prototype unileg multilayer generators from the currently best thermoelectric oxide Ca3Co4O9 are manufactured for the first time by industrially established ceramic multilayer technology. These generators exhibit a power density of 2.2 mW cm−2 at a temperature difference of 260 K, matching simulated values and confirming the suitability of the technology. Further design improvements increase the power density by a factor of 22 to facilitate practicable power output at temperature differences as low as 7 K. This work demonstrates that reasonable energy harvesting at elevated temperatures is possible with oxide materials and appropriate multilayer design. [ABSTRACT FROM AUTHOR]

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High-temperature devices are eco-friendly devices with the potential to become efficient systems for energy conversion and storage. The stability of components within solid oxide fuel cells and electrolyzers is related to their external operating conditions. The development of robust technologies that select suitable formulations to satisfy operational requirements is a critical issue. The segregation of cations on the surface, particularly of strontium at oxygen electrodes, exsolution of metal particles on anode electrodes, and ion interdiffusion in interlayer regions have a key influence. The segregation and interdiffusion of ions in electrochemical cell materials are critical to the chemical activity and stability of materials, as thermally induced chemical restructuring shapes their microstructure and morphology. The chemical composition of materials is affected by the redistribution of elements between different layers, surface segregation, and metal exsolution. This, in turn, contributes to the formation of low-conducting phases and poisoning phases. In recent years, computational methods and advanced technologies have enabled high-sensitivity examination of the microstructure of ceramic surfaces in the near-surface region. The literature review centers on recent advancements in the study of segregation processes. It covers theoretical calculations and modeling, segregation processes in single crystal and polycrystalline samples, the impact of polarization on cation mass transfer, interdiffusion processes, the influence of atmospheres on the process rates, and the exsolution processes of metal nanoparticles in reducing atmospheres or stepwise exsolution processes in oxidizing atmospheres. [ABSTRACT FROM AUTHOR]

Background and Objectives: The surge in breast-related surgeries in Korea underscores the critical need for an accurate early diagnosis of silicone breast implant-related issues. Complications such as BIA-ALCL and BIA-SCC add complexity to breast health concerns, necessitating vigilant monitoring. Despite advancements, discrepancies persist between ultrasonographic and pathologic classifications of silicone implant ruptures, highlighting a need for enhanced diagnostic tools. This study explores the reliability of ultrasonography in diagnosing silicone breast implant ruptures and determining the extent of silicone migration, specifically with a focus on guiding potential capsulectomy based on pathology. Materials and Methods: A comprehensive review of medical records encompassing 5557 breast implants across 2790 patients who underwent ultrasound-assisted examinations was conducted. Among the screened implants, 8.9% (249 cases) were diagnosed with silicone breast implant rupture through ultrasonography. Subsequently, 89 women underwent revisional surgery, involving capsulectomy. The pathological analysis of 111 periprosthetic capsules from these cases aimed to assess the extent of silicone migration, and the findings were juxtaposed with the existing ultrasonographic rupture classification. Results: The diagnostic agreement between preoperative sonography and postoperative findings reached 100% for silicone breast implant ruptures. All eighty prosthetic capsules exhibiting a snowstorm sign in ultrasonography demonstrated silicone migration to capsules upon pathologic findings. Conclusions: High-resolution ultrasonography emerged as a valuable and reliable imaging modality for diagnosing silicone breast implant ruptures, with a notable ability to ascertain the extent of free silicone migration to capsules. This diagnostic precision is pivotal in informing decisions about potential capsulectomy during revisional surgery. The study advocates for an update to the current binary ultrasonographic classification, suggesting a more nuanced categorization into three types (subcapsular, intracapsular, and extracapsular) based on pathology. [ABSTRACT FROM AUTHOR]

Context. 3C 84 is a nearby radio source with a complex total intensity structure, showing linear polarisation and spectral patterns. A detailed investigation of the central engine region necessitates the use of very-long-baseline interferometry (VLBI) above the hitherto available maximum frequency of 86 GHz. Aims. Using ultrahigh resolution VLBI observations at the currently highest available frequency of 228 GHz, we aim to perform a direct detection of compact structures and understand the physical conditions in the compact region of 3C 84. Methods. We used Event Horizon Telescope (EHT) 228 GHz observations and, given the limited (u, v)-coverage, applied geometric model fitting to the data. Furthermore, we employed quasi-simultaneously observed, ancillary multi-frequency VLBI data for the source in order to carry out a comprehensive analysis of the core structure. Results. We report the detection of a highly ordered, strong magnetic field around the central, supermassive black hole of 3C 84. The brightness temperature analysis suggests that the system is in equipartition. We also determined a turnover frequency of νm = (113 ± 4) GHz, a corresponding synchrotron self-absorbed magnetic field of BSSA = (2.9 ± 1.6) G, and an equipartition magnetic field of Beq = (5.2 ± 0.6) G. Three components are resolved with the highest fractional polarisation detected for this object (mnet = (17.0 ± 3.9)%). The positions of the components are compatible with those seen in low-frequency VLBI observations since 2017–2018. We report a steeply negative slope of the spectrum at 228 GHz. We used these findings to test existing models of jet formation, propagation, and Faraday rotation in 3C 84. Conclusions. The findings of our investigation into different flow geometries and black hole spins support an advection-dominated accretion flow in a magnetically arrested state around a rapidly rotating supermassive black hole as a model of the jet-launching system in the core of 3C 84. However, systematic uncertainties due to the limited (u, v)-coverage, however, cannot be ignored. Our upcoming work using new EHT data, which offer full imaging capabilities, will shed more light on the compact region of 3C 84. [ABSTRACT FROM AUTHOR]

Vanadium‐carbide‐based MXenes have bewitched the scientific community due to their distinctive characteristics, which make them potential candidates for several technological applications, such as supercapacitors (SCs), batteries, gas separation, biological sensors, and desalination. This article provides an overview of recent developments in the synthesis and applications of vanadium‐carbide MXene in SCs. Vanadium carbide is one of the most difficult MXenes to synthesize, and various synthesis techniques, including electrochemical exfoliation and chemical etching, have been utilized to fabricate this material. Additionally, the review article also emphasizes the potential use of vanadium carbide MXene as SCs. Finally, the paper concludes with the challenges faced in the synthesis process and the prospects of vanadium carbide MXene‐based material fabrication. Overall, this review article provides in‐depth and detailed information on recent research on vanadium carbide MXene and its possible uses. [ABSTRACT FROM AUTHOR]

The magnetotelluric (MT) responses are explicitly solved for a stratiform earth containing multiple transitional layers in which the conductivity varies linearly with depth. In the model under consideration, any one homogeneous layer with constant conductivity or transitional one may be absent in the geometry. The traditional one-dimensional (1D) models with sharp boundaries will be obtained if all the transitional layers are absent in the geometry, while a special 1D model consisting of a sequence of contiguous transitional layers may be obtained if all the homogeneous layers (except the basement layer) are removed from the geometry. The tangential electric and magnetic fields as well as the surface impedance are analytically expressed by Airy functions. The analytical formula is validated in three theoretical examples by comparing with the results from available codes. The apparent resistivity and impedance phase on the surface of three different transitional models are illustrated to analysis the influence of the transitional layers on MT responses. The new formula provides an alternative way to obtain the analytic MT responses for the special layered earth. [ABSTRACT FROM AUTHOR]

The physical properties of perovskite oxide thin films are governed by the subtle interplay between chemical composition and crystal symmetry variations, which can be altered by epitaxial growth. In the case of perovskite-type multiferroic thin films, precise control of stoichiometry and epitaxial strain allows for gaining control over the ferroic properties through selective crystal distortions. Here, we demonstrate the chemical tailoring of the polar atomic displacements by tuning the stoichiometry of multiferroic Sr1−xBaxMnO3−δ (0 ≤ x ≤ 0.5) epitaxial thin films. A combination of x-ray diffraction and aberration-corrected scanning transmission electron microscopy enables unraveling the local polarization orientation at the nanoscale as a function of the film's composition and induced crystalline structure. We demonstrate experimentally that the orientation of polarization is intimately linked to the Ba doping and O stoichiometry of the films and, with the biaxial strain induced by the substrate, it can be tuned either in-plane or out-of-plane with respect to the substrate by the appropriate choice of the post-growth annealing temperature and O2 atmosphere. This chemistry-mediated engineering of the polarization orientation of oxide thin films opens new venues for the design of functional multiferroic architectures and the exploration of novel physics and applications of ferroelectric textures with exotic topological properties. [ABSTRACT FROM AUTHOR]

Two-step thermochemical H2O/CO2 splitting offers a promising approach to convert intermittent solar energy into storable fuels. However, achieving efficient reaction kinetics in dense particles requires a comprehensive understanding of the bulk diffusion, surface reactions and concentration of local species. In this study, we present a comprehensive 1-D numerical model that accounts for gas–solid mass transfer, surface reactions, and bulk diffusion in reacting particles. The model was validated using previously reported experimental data for CeO2 in the temperature range from 1173 to 1473 K. We used a resistance model to accurately quantify the rate-limiting steps. Our findings indicated that surface kinetics generally represent the primary limiting factor for small particle sizes, and the particles with a radius exceeding 60 μm, undergoing reduction at an oxygen partial pressure equal to 10−8 atm, experience rate limitations due to gas-phase mass transfer. In contrast, under extreme conditions, such as particle radius of 1 cm and diffusion coefficient of less than 10−6 cm2 s−1, bulk diffusion became one of the rate-limiting steps. This comprehensive modeling approach has potential to be applied to other candidate materials in thermochemical cycles, enabling fast material screening and structural designs. [ABSTRACT FROM AUTHOR]

In this paper, La 1 − x CaxFeO3 (x = 0 , 0.1, 0.2, 0.3, 0.4, 0.5) perovskite samples were synthesized by sol–gel method. X-ray diffraction (XRD), transmission electron microscopy (TEM) and Mössbauer were used for measuring. XRD measurement shows that the unit cell volume of LaFeO3 gradually decreases with increasing Ca content. The morphology of the sample was observed by TEM, and there were significant changes in volume and size of the samples with different calcium contents. Mössbauer spectrum study found that with the gradual increase of Ca content, Fe 3. 5 + and Fe 4 + were formed in the sample. The study in this paper will provide a reference for future research on the effect of different calcium contents on the electronic structure of lanthanide ferrite. [ABSTRACT FROM AUTHOR]

Thermal energy storage (TES) based on phase change materials (PCM) is an effective strategy to reduce energy consumption in buildings. The efficient implementation of TES in building through PCMs, requires modification of their thermal performance, appropriate design and evaluation of their thermal and economic efficiency. One major challenge in the application of PCMs is the selection of high-performance and environmental-friendly supporting materials to overcome the most critical drawback of PCMs (solid-to-liquid transition and resulting leakage). This review focuses on expanded clay (EC) lightweight aggregate (LWA), as one of the promising supporting materials for development of form-stabilized PCM (FSPCM) in the lightweight concrete (LWC) industry. The large specific surface area and porous structure of expanded clay can maintain considerable amount of PCM. In addition, mechanical properties and compatibility with various PCMs make EC a suitable carrier. A detailed review of available researches is presented to elucidate the properties of PCMs embedded in EC for thermally efficient cement-based concrete. Various combinations of EC with the most used PCMs, thermal and mechanical properties of matrices containing PCM-EC, strategies to improve the efficiency of PCM performance, and finally the impact of PCM-EC based concretes on the thermal comfort of buildings are critically summarized. [ABSTRACT FROM AUTHOR]

Calcium cobaltite Ca3Co4−xO9+δ (CCO) is a promising p‐type thermoelectric (TE) material for high‐temperature applications in air. The grains of the material exhibit strong anisotropic properties, making texturing and nanostructuring mostly favored to improve thermoelectric performance. On the one hand multitude of interfaces are needed within the bulk material to create reflecting surfaces that can lower the thermal conductivity. On the other hand, low residual porosity is needed to improve the contact between grains and raise the electrical conductivity. In this study, CCO fibers with 100% flat cross sections in a stacked, compact form are electrospun. Then the grains within the nanoribbons in the plane of the fibers are grown. Finally, the nanoribbons are electrospun into a textured ceramic that features simultaneously a high electrical conductivity of 177 S cm−1 and an immensely enhanced Seebeck coefficient of 200 µV K−1 at 1073 K are assembled. The power factor of 4.68 µW cm−1 K−2 at 1073 K in air surpasses all previous CCO TE performances of nanofiber ceramics by a factor of two. Given the relatively high power factor combined with low thermal conductivity, a relatively large figure‐of‐merit of 0.3 at 873 K in the air for the textured nanoribbon ceramic is obtained. [ABSTRACT FROM AUTHOR]

Solid Oxide Electrolysis Cells (SOECs) have proven to be a highly efficient key technology for producing valuable chemicals and fuels from renewably generated electricity at temperatures between 600 °C and 900 °C, thus providing a carbon-neutral method for energy storage. The successful implementation of this technology on an industrial level in particular requires the long-term stability of all system components with a concurrent overall degradation rate of a maximum of 0.75% kh−1 or even better 0.5% kh−1, corresponding to a performance loss of 20% over approx. five years under constant operating parameters. However, the materials currently used for SOEC systems have been developed and optimized in recent decades for fuel cell operation. The degradation of these Solid Oxide Fuel Cell (SOFC) materials used in SOECs, however, slows down the technology and market ramp-up. Accordingly, a selection and development of materials specifically for use in SOEC operation, must therefore be based not only on the highest performance but also on the lowest achievable degradation rate. In general, the systematic development of new SOEC materials must be driven towards key performance parameters such as mechanical, thermal, and chemical stability as well as an application-oriented assessment (cost effectiveness, simple manufacturing). This review presents the state-of-the-art materials in current industrial use for planar SOECs as well as future challenges regarding materials design and degradation. Recent advances in material compositions are discussed and evaluated in terms of their performance, stability, and potential for industrial implementation. In addition, a materials selection for interconnects, coatings, and sealants is briefly listed to outline current developments in these areas. [ABSTRACT FROM AUTHOR]

The exploration of new and efficient sulfur cathodes through nanostructured materials design is vital for the development of high‐performance metal–sulfur batteries, which is a promising candidate for next‐generation energy storage systems. However, the shuttle behavior and sluggish reaction kinetics of polysulfides hinder the application of sulfur cathodes. Herein, a 3D MXene/reduced graphene oxide (rGO) composite conductive framework with superior specific surface area, structural stability, and ionic/electronic conductivity is constructed. On this basis, the TiO2 nanoparticles, in situ grown in the interlayer between MXene and rGO can be used as adsorptive and catalytic active site for polysulfides to accelerate the electrochemical reaction kinetics and alleviate the shuttle effect, thereby improving cycle stability. Consequently, the sulfur‐loaded MXene‐TiO2@rGO composite electrodes present a high reversible capacity of 1052.0 mAh g−1 at 0.2 C after 200 cycles, favorable high‐rate capability, and splendid long‐term performance, retaining 445.6 mAh g−1 capacity after 1000 cycles at 2 C in hybrid Mg/Li–S batteries. This work provides a new insight for using MXene as the sulfur host with high performance for metal–sulfur batteries. [ABSTRACT FROM AUTHOR]

Herein, perovskite La0.64(Ba1−xCax)0.36FeO3−δ (0≤x≤0.4$0 \leq x \leq 0.4$) samples are synthesized and investigated by X‐ray diffraction and mechanical spectroscopy. The room‐temperature structure of La0.64Ba0.36FeO3−δ is a mixture of orthorhombic and cubic phases. The structures of calcium‐doped La0.64(Ba1−xCax)0.36FeO3−δ are orthorhombic at room temperature. A modulus dip is observed above room temperature in La0.64(Ba1−xCax)0.36FeO3−δ (0≤x≤0.4$0 \leq x \leq 0.4$) samples. This corresponds to a phase transition from orthorhombic to rhombohedral structure with increasing temperature. The effect of oxygen nonstoichiometry on the room‐temperature structure and phase transition is observed by mechanical spectroscopy. [ABSTRACT FROM AUTHOR]

The controlled source electromagnetic (CSEM) method is frequently used as a risk reduction tool in hydrocarbon exploration. This paper aims to provide a comprehensive historical review of the CSEM method's twenty-year history in the Brazilian continental margin. Since 2003, we have significantly improved our understanding of CSEM resistivity data across various geological scenarios. This review presents a roadmap of the technical advancements in acquisition design and interpretation techniques. As a result, our understanding of the methodology has broadened from traditional to more general use, such as salt imaging, gas hydrates, geohazard mapping, and reservoir characterization. Finally, we indicate the potential upcoming CSEM applications in new energy resources and carbon capture and storage. [ABSTRACT FROM AUTHOR]

Perovskite oxides have been widely confirmed as a promising alternative to precious metals as catalysts for a wide range of environmental protection, energy storage, and conversion devices for their prominent intrinsic electrocatalytic activity, flexible structure, low cost, and easy synthesis. Since its discovery in 1839, perovskite oxide has been the subject of a considerable amount of systematic research in several exploring aspects (e. g., materials synthesis, component regulation, and catalytic properties). The above‐mentioned findings have been extensively reviewed and consolidated in numerous publications. The heterogeneous catalytic performance of perovskite oxides has been significantly affected by their surface composition, electronic structure, and defect chemistry. This study places a focus on the crystal structure and structure regulation of ordered perovskite oxides. Moreover, the recent research progress in areas (e. g., perovskite surface element segregation, law of exsolution, and the mechanism of exsolution) is systematically reviewed. Furthermore, this study highlights potential future directions for the development of perovskite oxides. [ABSTRACT FROM AUTHOR]

The perovskite-type oxide Ba0.5Sr0.5Co0.8Fe0.2O3−δ is a superlative mixed ionic–electronic conductor but has low chemical stability that severely limits its use. Using molecular dynamics simulations, we predict that substituting Ba with Ca yields a material, Ca0.5Sr0.5Co0.8Fe0.2O3−δ, that in its cubic form exhibits similarly high oxygen-vacancy diffusivity. [ABSTRACT FROM AUTHOR]

We observed the flat-spectrum radio quasar 4C 29.45 in the BVRI optical bands for 39 nights from February 2022 to July 2022 with the T60 telescope at TÜBİTAK National Observatory (TUG) in Turkey. In this study, we aimed to study flux, color, and spectral variability on short timescales. The object was in an active (bright) phase with an average optical R-band brightness of 14.7 mag and was variable in the BVRI bands throughout the monitoring period. We analyzed the flux variability during our observation period, and the variability amplitudes in V, R, and I bands were determined to be 220%, 208%, and 209%, respectively. Optical spectral energy distributions of 4C 29.45 were derived from the observational data of 33 nights, indicating spectral indices ranging from 1.032 to 1.573. We found modest correlations between optical light curves, and between R-band light curve and spectral indices, suggesting that the time lag ranges from several hours to days. Investigation on relation between spectral and color indices versus R-band magnitude revealed achromatic trend during the bright phase of 4C 29.45 in the first half of 2022. Our periodicity search suggested that the periodicity would be larger than 100 days, and no significant signal for periodicity was found for short timescales. [ABSTRACT FROM AUTHOR]

CaMnO3−δ-based perovskites find application in a variety of thermochemical cycles, e.g. oxygen partial pressure adjustment, chemical looping processes, and thermochemical energy storage. The applicability of these materials is governed by their thermodynamic and kinetic properties. Therefore, tunability of these properties is desirable to adapt the material to the required conditions. In this study, the effect of Sr content in Ca1−xSrxMnO3−δ on thermodynamics and kinetics is investigated by thermogravimetric analysis. The thermodynamics are measured in the temperature range of 873 K to 1473 K with oxygen partial pressures of 1 × 10−4 bar to 0.8 bar. The oxidation kinetics were characterized in the temperature range from 473 K to 673 K with oxygen partial pressures of 0.01 bar to 1 bar. The reduction kinetics were very rapid in the temperature range of 873 K to 1023 K, with the measured rates limited by the constraints of the measurement device. The results show that with increasing Sr content the structural changes of the material decrease the reduction enthalpy and the oxidation activation energy. This not only leads to a tunability of material properties, but can also be used to predict changes of these properties when only the structural changes are known. [ABSTRACT FROM AUTHOR]

Astronauts suffer from natural space radiation as high-energetic protons, heavy ions, and secondary particles produced in collisions. Galactic cosmic rays and solar particle events are the basic parts of space radiation spectra. Wears and accessories designs for use by astronauts aim to minimize these deleterious effects of this environment. Polymeric materials are preferred in astronaut suits because they are lightweight, inexpensive, and durable. Teflon, KEVLAR, ethylene tetrafluoroethylene, DYNEEMA, and NOMEX polymeric astronaut wear materials were exposed to high energetic proton irradiations by the use of Monte Carlo simulation tools SRIM-2013 and FLUKA 2011.1. Proton energies are applied as 1, 2, and 3 GeV known as in order of space radiation magnitude. Besides, displacement per atom calculations were done and results were discussed in the plane of structural changes in the given polymeric materials. After interacting with protons with 1, 2, and 3 GeV energies, the material with the lowest Displacement per atom value among the five studied materials is DYNEEMA with values of 1.01E − 25, 9.96E − 26, and 1.00E − 25, respectively. Again, among the materials studied for these three proton energies, DYNEEMA has the highest electronic stopping power values are, respectively, 2.11E − 03, 2.10E − 03, and 2.31E − 03. DYNEEMA has the highest nuclear stopping power values as 2.23E − 07, 1.53E − 07, and 4.27E − 07, respectively. [ABSTRACT FROM AUTHOR]

Measuring and inferring the key physical parameters of jets in active galactic nuclei (AGN) requires high-resolution very long baseline interferometry (VLBI) observations. Using VLBI to measure a core-shift effect is a common way of obtaining estimates of the jet magnetic field strength, a key parameter for understanding jet physics. The VLBI core is typically identified as the bright feature at the upstream end of the jet, and the position of this feature changes with the observed frequency, rcore / 1=kr. Due to the variable nature of AGN, flares can cause variability of the measured core shift. In this work, we investigated the time variability of the core-shift effect in the luminous blazar 3C 454.3. We employed a self-referencing analysis of multi-frequency (5, 8, 15, 2224, and 43 GHz) Very Long Baseline Array (VLBA) data covering 19 epochs from 2005 to 2010. We found significant core-shift variability ranging from 0.27 to 0.86 milliarcsec between 5 GHz and 43 GHz. These results confirm the core-shift variability phenomenon observed previously. Furthermore, we also found time variability of the core-shift index, kr which was typically below one, with an average value of 0:85 0:08 and a standard deviation of 0:30. Values of kr below one were found during flaring and quiescent states. Our results indicate that the commonly assumed conical jet shape and equipartition conditions do not always hold simultaneously. Even so, these conditions are typically assumed when deriving magnetic field strengths from core-shift measurements, which can lead to unreliable results if kr significantly deviates from unity. Therefore, it is necessary to verify that kr = 1 actually holds before using core-shift measurements and the equipartition assumption to derive physical conditions in the jets. When kr = 1 epochs are selected in the case of 3C 454.3, the magnetic field estimates are consistent, even though the core shift varies significantly with time. Subsequently, we estimated the magnetic flux in the jet of 3C 454.3 and found that the source is in the magnetically arrested disc state, which agrees with earlier studies. Finally, we found a good correlation of the core position with the core flux density, rcore / S 0:7 core, which is consistent with increased particle density during the flares. [ABSTRACT FROM AUTHOR]

Sulfur‐based batteries are regarded as potent candidates for next‐generation high‐energy and low‐cost energy storage systems. However, sulfur‐based batteries still face substantial obstacles on the cathode side (e.g., low conductivity and sluggish reaction kinetics of sulfur) and the anode side (e.g., dendrite growth), severely hindering their utilization. MXenes (i.e., 2D transition metal carbides, nitrides, and carbonitrides), as an emerging member of the 2D material family, possess unique electrochemical and electronic properties, which make them attractive materials to enhance the performance of sulfur‐based batteries. In this article, a comprehensive review of the research progress on using MXenes in sulfur‐based batteries is provided. The basics of MXene and sulfur‐based batteries are introduced first, wherein the merits of applying MXenes in sulfur‐based batteries are discussed. Subsequently, the progress in this field is systematically summarized in terms of the roles of MXene in sulfur‐based batteries, including MXene as sulfur host, MXene‐based composite as sulfur host, MXene‐based separator modification, and MXene‐based advanced electrodes. In the end, recommendations for specific future research directions to advance the development of MXenes for sulfur‐based batteries are outlined. [ABSTRACT FROM AUTHOR]

La0.6Sr0.4FeO3−δ (LSF) electrodes were grown on different electrolyte substrates by pulsed laser deposition (PLD) and their oxygen exchange reaction (OER) resistance was tracked in real-time by in situ PLD impedance spectroscopy (i-PLD) inside the PLD chamber. This enables measurements on pristine surfaces free from any contaminations and the direct observation of thickness dependent properties. As substrates, yttria-stabilized zirconia single crystals (YSZ) were used for polycrystalline LSF growth and La0.95Sr0.05Ga0.95Mg0.05O3−δ (LSGM) single crystals or YSZ single crystals with a 5 nm buffer-layer of Gd0.2Ce0.8O2−δ for epitaxial LSF film growth. While polycrystalline LSF electrodes show a constant OER resistance in a broad thickness range, epitaxially grown LSF electrodes exhibit a continuous and strong increase of the OER resistance with film thickness until ≈60 nm. In addition, the activation energy of the OER resistance increases by 0.23 eV compared to polycrystalline LSF. High resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) measurements reveal an increasing contraction of the out-of-plane lattice parameter in the epitaxial LSF electrodes over electrode thickness. Defect thermodynamic simulations suggest that the decrease of the LSF unit cell volume is accompanied by a lowering of the oxygen vacancy concentration, explaining both the resistive increase and the increased activation energy. [ABSTRACT FROM AUTHOR]

Sustainable hydrogen production is one of the most important topics in modern energy economics. Of technological relevance are, for example, electrochemical and thermal splitting of water. For such processes anode materials with a variable concentration of oxygen defects are required. Herein, the oxygen defect thermochemistry of a possible anode material, the perovskite CaMnO3, is investigated theoretically. The aim of this work is to identify reliable quantum chemical methods for the calculation of oxygen defect formation enthalpies and entropies, including configuration entropy, which is usually neglected. All possible defect configurations in a supercell are computed to obtain the configuration entropy using Boltzmann statistics. Various generalized gradient approximation (GGA), meta‐GGA, and hybrid functionals as implemented in the solid‐state programs CRYSTAL and VASP are evaluated for the calculation of structure parameters, electronic and magnetic properties, and reaction energies of CaMnO3. The global hybrid functional PW1PW gives the most accurate overall description of CaMnO3 and is therefore recommended for future theoretical studies of more efficient water‐splitting catalysts based on calcium manganate. [ABSTRACT FROM AUTHOR]

(Sr 0.95 La 0.05) 0.95 □ 0.05 TiO 3 ceramics were prepared by solid state reaction and sintered by spark plasma sintering at different temperatures ranging from 1473 to 1873 K for 10 min. The thermoelectric properties show that sintering at temperatures higher than 1773 K allows reaching high thermoelectric properties similar to the ones obtained after annealing at high temperatures in H 2 / N 2 for several hours. The high temperature sintered samples exhibit highest power factor near room temperature, resulting in ZT values higher than 0.1. Therefore, the 10 min short SPS process at high temperatures described in this paper is an easy, cheap, fast, and one step route to obtain dense and efficient SrTiO 3 -based thermoelectric ceramics. However, SEM observations show that the samples are not pure perovskite phase but contain titanium oxide and lanthanum compound aggregates. [ABSTRACT FROM AUTHOR]

Perovskite oxides of the general formula ABO3−δ, with A and B being metal cations, present themselves in various crystal structures that originate from a distorted ideal cubic perovskite. Understanding how composition, temperature, atmosphere and reduction extent of these non-stoichiometric redox materials induce structural changes on an atomic, as well as macroscopic, level is crucial to transfer newly developed materials to industrial scale applications in the redox-based energy conversion sector. Herein, Ca1−xSrxMnO3−δ (x ∈ [0,0.2]) and its micro- and macroscopic structural changes at elevated temperatures and varying oxygen partial pressure are analyzed by means of in situ high temperature XRD, DSC and dilatometry. Results are expanded by room temperature XRD of compositions with higher Sr-content up to x = 0.4. By adjusting the Sr-content, the formed crystal structure can be governed and thermal expansion can be impacted beneficially in the context of future applications utilizing monolithic structures. Phase transitions from orthorhombic to cubic were found to shift from 900 °C to 830 °C under air and to even lower temperatures under 1% O2 atmosphere. Small amounts of Sr-content (5–10%) stabilize the macroscopic structural integrity by improving the reversibility of the cyclic thermal expansion and contraction in a 1% O2 atmosphere. However, at Sr-contents of 20% an increased irreversible residual expansion within each thermal cycle becomes apparent and shows that such improvements do not follow a linear dependency with Sr-content, but most benefits in this context can be found at Sr-contents below 20%. The results demonstrate the sensitivity of such materials micro- and macroscopic characteristics to composition. In the context of utilization of monolithic structures, fabricated entirely from Ca1−xSrxMnO3−δ, in thermochemical or thermoelectric applications, the results have considerable significance as minor A-site Sr-substitution can substantially improve macroscopic stability of monolithic structures over multiple thermal cycles. Besides the often solely regarded thermodynamic characteristic, this work demonstrates the importance to consider the impact of composition on structural behavior in materials design processes including perovskites for thermochemical applications. [ABSTRACT FROM AUTHOR]

The next generation of fuel cells, electrolyzers, and batteries requires higher power, faster kinetics, and larger energy density, which necessitate the use of compositionally complex oxides to achieve multifunctionalities and activity. These compositionally complex oxides may change their phases and structures during an electrochemical process—a so-called 'electrochemically driven phase transformation.' The origin for such a phase change has remained obscure. The aim of this paper is to present an experimental study and a theoretical analysis of phase evolution in praseodymium nickelates. Nickelate-based electrodes show up to 60 times greater phase transformation during operation when compared with thermally annealed ones. Theoretical analysis suggests that the presence of a reduced oxygen partial pressure at the interface between the oxygen electrode and the electrolyte is the origin for the phase change in an oxygen electrode. Guided by the theory, the addition of the electronic conduction in the interface layer leads to the significant suppression of phase change while improving cell performance and performance stability [ABSTRACT FROM AUTHOR]

Perovskite-type manganite-based ceramics are a promising thermoelectric material at high temperature, while their poor electrical resistivity and thermal conductivity restrict their application in thermoelectricity generators. Entropy engineering can optimize the thermoelectric performance in both electron transport and phonon scattering. RE0.2Ca0.2Sr0.2Ba0.2Y0.2MnO3 (RE = La, Nd, Ho, Lu) ceramics were prepared by using a solid state method. It is clearly confirmed that a high-entropy perovskite-type solid solution with some metallic oxides was obtained and all the A-site elements were dispersed homogeneously. A-site deficiency induced lattice disorders, stacking faults and sparse dislocation, were formed enhancing phonon scattering. A minimum total thermal conductivity of 0.94 W m−1 K−1 was obtained at 800 °C. With the increase of measured temperatures, the power factors and ZT values increased first and then decreased. The maximum power factor value of 25.3 μW m−1 K−2 was achieved at 600 °C for the La0.2Ca0.2Sr0.2Ba0.2Y0.2MnO3 sample. This work suggests that the strategy of high-entropy engineering paves a novel way for synergistically optimizing the thermoelectric performance of oxide ceramics. [ABSTRACT FROM AUTHOR]