Solids

Noncoplanar spin textures give rise not only to unusual magnetic structures but also to emergent electromagnetic responses stemming from scalar spin chirality, such as the topological Hall effect. In this study, we theoretically investigate nonreciprocal transport phenomena induced by noncoplanar magnetic orderings through microscopic model analyses. By focusing on meron–antimeron spin textures that exhibit local scalar spin chirality while maintaining vanishing global chirality, we demonstrate that the electronic band structure becomes asymmetrically modulated, which leads to the emergence of nonreciprocal transport. The present mechanism arises purely from the noncoplanar magnetic texture itself and requires neither net magnetization nor relativistic spin–orbit coupling. We further discuss the potential relevance of our findings to the compound Gd₂PdSi₃, which has been suggested to host a meron–antimeron crystal phase at low temperatures. Full article

Tungsten and tungsten alloys are widely used in important industrial fields due to their high density, hardness, melting point, and corrosion resistance. However, machining often leaves processing marks on their surface, significantly affecting the surface quality of precision components in industrial applications. Electrolytic polishing offers high efficiency, low workpiece wear, and simple processing. In this study, an electrolytic polishing method is adopted and a novel trisodium phosphate–sodium hydroxide electrolytic polishing electrolyte is developed to study the effects of temperature, voltage, polishing time, and solution composition on the surface roughness of a tungsten–nickel–iron alloy. The optimal voltage, temperature, and polishing time are determined to be 15 V, 55 °C, and 35 s, respectively, when the concentrations of trisodium phosphate and sodium hydroxide are 100 g·L⁻¹ and 6 g·L⁻¹. In addition, glycerol is introduced into the electrolyte as an additive. The calculated LUMO value of glycerol is −5.90 eV and the HOMO value is 0.40 eV. Moreover, electron enrichment in the hydroxyl region of glycerol can form an adsorption layer on the surface of the tungsten alloy, inhibit the formation of micro-pits, balance ion diffusion, and thus promote the formation of a smooth surface. At 100 mL·L⁻¹ of glycerol, the roughness of the tungsten–nickel–iron alloy decreases significantly from 1.134 μm to 0.582 μm. The electrochemical polishing mechanism of the tungsten alloy in a trisodium phosphate electrolyte is further investigated and explained according to viscous film theory. This study demonstrates that the trisodium phosphate–sodium hydroxide–glycerol electrolyte is suitable for electropolishing tungsten–nickel–iron alloys. Overall, the results support the application of tungsten–nickel–iron alloy in the electronics, medical, and atomic energy industries. Full article

Two-dimensional (2D) crystals which present unconventional stoichiometries on graphene surfaces in ambient conditions, such as Na₂Cl, Na₃Cl, and CaCl, have attracted significant attention in recent years due to their electronic structures and abnormal cation–anion ratios, which differ from those of conventional three-dimensional crystals. This unconventional crystallization is attributed to the cation–π interaction between ions and the π-conjugated system of the graphene surface. Consequently, their physical and chemical properties—including their electrical, optical, magnetic, and mechanical characteristics—often differ markedly from those of conventional crystals. This review summarizes the recent progress made in the fabrication and analysis of the structures, distinctive features, and applications of these 2D unconventional stoichiometry crystals on graphene surfaces in ambient conditions. Their special properties, including their piezoelectricity, metallicity, heterojunction, and room-temperature ferromagnetism, are given particularly close attention. Finally, some significant prospects and further developments in this exciting interdisciplinary field are proposed. Full article

Polylactic acid (PLA) fabrics exhibit significant sunlight reflectivity and high emissivity within the atmospheric window, making them suitable as the foundational material for this study. This research involves the modification of one side of the fabric with hydrophilic agents and titanium dioxide (TiO₂), while the opposite side is treated with MXene and subsequently coated with polydimethylsiloxane (PDMS) to inhibit oxidation of the MXene. Through these surface modifications, a thermal management fabric based on PLA was successfully developed, capable of passively regulating temperature in response to environmental conditions and user requirements. The study discusses the optimal concentrations of TiO₂ and MXene for the fabric, and characterizes and evaluates the functional surface of the PLA. Surface morphology analyses and tests indicate that the resulting functional PLA fabrics possess excellent ultraviolet (UV) resistance, favorable air permeability, high sunlight reflectivity on the TiO₂-treated side, and superior photothermal conversion capabilities on the MXene-treated side. Furthermore, photothermal effect tests conducted under a light intensity of 1000 W/m² reveal that the MXene-treated fabric exhibits a heating effect of approximately 25 °C, while the TiO₂-treated side demonstrates a cooling effect exceeding 5 °C. This study developed PLA functional fabrics with heating and cooling capabilities. Full article

This study employs molecular dynamics (MD) simulations to investigate the mechanical response and fracture behavior of penta-graphene, a novel two-dimensional carbon allotrope composed entirely of pentagonal rings with mixed sp²–sp³ hybridization and pronounced mechanical anisotropy. Atomistic simulations are carried out to evaluate the impact of structural defects on mechanical performance and to elucidate crack propagation mechanisms. The results reveal that void defects involving sp³-hybridized carbon atoms cause a more significant degradation in mechanical strength compared to those involving sp² atoms. During fracture, local atomic rearrangements and bond reconstructions lead to the formation of energetically favorable ring structures—such as hexagons and octagons—at the crack tip, promoting enhanced energy dissipation and fracture resistance. A central focus of this work is the evaluation of the critical stress intensity factor (SIF) under mixed-mode (I/II) loading conditions. The simulations demonstrate that the critical SIF is influenced by the loading phase angle, with pure mode I exhibiting a higher SIF than pure mode II. Notably, penta-graphene shows a critical SIF significantly higher than that of graphene, indicating exceptional fracture toughness that is rare among ultra-thin two-dimensional materials. This enhanced toughness is primarily attributed to penta-graphene’s capacity for substantial out-of-plane deformation prior to failure, which redistributes stress near the crack tip, delays crack initiation, and increases energy absorption. Additionally, the study examines crack growth paths as a function of loading phase angle, revealing that branching and kinking can occur even under pure mode I loading. Full article

The cements industry is increasingly under pressure to reduce carbon emissions while maintaining performance standards. Limestone calcined clay cement (LC³) presents a promising low-carbon alternative; however, its performance depends significantly on the type and reactivity of clay used. This study investigates the effect of three common low-grade clay minerals—kaolinite, montmorillonite, and illite—on the behavior of LC³ blends. The clays were thermally activated and characterized using X-ray diffraction (XRD), thermogravimetric analysis (TGA), X-ray fluorescence spectroscopy (XRF), and Blaine air permeability testing to evaluate their mineralogical composition, thermal behavior, chemical content, and fineness. Pozzolanic reactivity was assessed using the modified Chapelle test. Microstructural development was examined through scanning electron microscopy (SEM) of the hydrated specimens at 28 days. The results confirmed a strong correlation between clay reactivity and hydration performance. Kaolinite showed the highest reactivity and fineness, contributing to a dense microstructure with reduced portlandite and enhanced formation of calcium silicate hydrate. Montmorillonite demonstrated comparable strength and favorable hydration characteristics, while illite, though less reactive initially, showed acceptable long-term behavior. Although kaolinite delivered the best overall performance, its limited availability and higher cost suggest that montmorillonite and illite represent viable and cost-effective alternatives, particularly in regions where kaolinite is scarce. This study highlights the suitability of regionally available, low-grade clays for use in LC³ systems, supporting sustainable and economically viable cement production. Full article

Perovskite bionic eyes have emerged as highly promising candidates for photodetection applications to their wide-angle imaging capabilities, high external quantum efficiency(EQE), and low-cost fabrication and integration. Since their initial exploration in 2015, significant advancements have been achieved in this field, with their EQE reaching 27%. Nevertheless, intrinsic challenges such as the oxidation susceptibility of perovskites and difficulties in curved surface growth hinder their further development. Addressing these issues necessitates a comprehensive and systematic understanding of the preparation mechanisms for hemispherical perovskite, as well as the development of effective mitigation strategies. In this review, a review published provides a detailed overview of the research progress in hemispherical perovskite photodetectors, with a particular focus on the fundamental properties and fabrication pathways of hemispherical perovskites. Furthermore, various strategies to enhance the performance of hemispherical perovskite and overcome preparation challenges are thoroughly discussed. Finally, existing challenges and perspectives are presented to further advance the development of eco-friendly hemispherical perovskite. Full article

With a low surface recombination velocity, it is possible to increase the efficiency of solar cells as the thickness is decreased. A maximum appearing in the efficiency versus thickness curve is mostly due to the same trend in the short-circuit current versus thickness curve. The trend of the short-circuit current versus thickness curve will be clearly discussed based on the view of competition between generation and recombination rates near the rear surface. If surface passivation can be well introduced, the win-win situation for the material cost and efficiency can be achieved based on our results. Full article

Understanding how crystal structure influences electronic properties is crucial for discovering new functional materials. In this study, we utilized Kernel Principal Component Analysis (KPCA) to classify and analyze the Density of States (DOS) of transition metal sulfide (TMS) compounds, particularly copper-based sulfides. By mapping high-dimensional DOS data into a lower-dimensional space, we identify clusters corresponding to different crystal systems and detect outliers with significant deviations from their expected groups. These outliers exhibit unusual electronic configurations, suggesting potential applications in semiconductors, thermoelectric devices, and optoelectronic devices. Projected Density of States (PDOS) analysis further reveals how orbital hybridization governs the electronic structure of these materials, highlighting key differences between structurally similar compounds. Additionally, we analyze phase stability through inter-cluster distance measurements, identifying potential phase transformations between closely related structures. The implications for this work in terms of modifying chemistries and generalized DOS predictions are discussed. Full article

This study presents the first comprehensive theoretical investigation utilizing SCAPS-1D simulation to systematically evaluate eight hole transport materials for CsPbI₂Br perovskite solar cells under authentic indoor LED conditions (560 lux, 5700 K color temperature). Unlike previous studies employing simplified illumination assumptions, our work establishes fundamental design principles for indoor photovoltaics through rigorous material property correlations. The investigation explores the influence of layer thickness and defect concentration on performance to identify optimal parameters. Through detailed energy band alignment analysis, we demonstrate that CuI achieves superior performance (PCE: 23.66%) over materials with significantly higher mobility, revealing that optimal band alignment supersedes carrier mobility under low-light conditions. Analysis of HTL and absorber layer thickness, bulk defect concentration, interface defect density, and an HTL-free scenario showed that interface defect concentration and absorber layer parameters have greater influence than HTL thickness. Remarkably, ultra-thin HTL layers (0.04 μm) maintain >99% efficiency, offering substantial cost reduction potential for large-scale manufacturing. Under optimized conditions of a 0.87 μm absorber layer thickness, defect concentration of 10¹⁵ cm⁻³, interface defect concentration of 10⁹ cm⁻³, and CuI doping concentration of 10¹⁷ cm⁻³, PCE reached 28.57%, while the HTL-free structure achieved 17.6%. This study establishes new theoretical foundations for indoor photovoltaics, demonstrating that material selection criteria differ fundamentally from outdoor applications. Full article

In the quest for stable, lead-reduced perovskites, this study unravels the structural and electronic evolution of CsZnI₃ across its α, β, and γ phases. DFT calculations spotlight the tetrahedral γ phase—with elongated Zn–I bonds (3.17 Å)—as the most stable, sidestepping the octahedral distortions of its metallic α and β counterparts. Pb²⁺ doping (>50%) drives a transformation to mixed octahedral–tetrahedral coordination, slashing the wide 3.15 eV bandgap to a solar-optimal 2.20 eV via lattice shrinkage. Above 50% doping, an optimum emerges—balancing structural integrity with efficient light absorption. These findings elevate Zn-doped or Zn-Pb-based compounds as promising and tunable perovskites for next-gen photovoltaics. Full article

This study investigates the potential correlation between C—H···Br and N—H···Br hydrogen bonds in CH₃NH₃PbBr₃ over a broad temperature range (50–350 K), using a statistical analysis of molecular dynamics simulations. The analysis focused on quantifying the relationship between both hydrogen bond types via Pearson and Spearman correlation coefficients, derived from extensive datasets obtained from simulation trajectories. The results revealed a notable discrepancy between the two coefficients at low temperatures (T ≤ 125 K): While Spearman’s values suggested a strong monotonic correlation, Pearson’s values indicated a lack of linear association. Further analysis through data segmentation and block averaging demonstrated that the high Spearman coefficients at low temperatures were not statistically robust. At higher temperatures (T > 125 K), both correlation coefficients consistently exhibited low values, confirming the absence of meaningful correlation. These findings suggest that the formation of C–H···Br and N–H···Br hydrogen bonds occurs independently, with no evidence of cooperative behavior. Full article

Global cement manufacturing generated 1.6 billion metric tons of CO₂ in 2022 and relies heavily on non-renewable raw materials. Utilizing agro-industrial waste as supplementary cementitious material (SCM) can help mitigate the demand for these resources. SCMs have been integrated into cement production to deliver both technical and environmental benefits to mortars and concrete. This study examines mortar blends containing blast furnace slag (BFS), Brazilian calcined clay (BCC), and bamboo leaf ash (BLA). While BFS and BCC are already established in the cement industry, recent research has highlighted BLA as a promising pozzolanic material. The SCMs were characterized, and mortars were produced to assess their flexural and compressive strength, as well as durability indicators such as electrical resistivity, chloride diffusion, migration coefficient, and carbonation resistance. The findings reveal significant performance enhancements. Partial cement replacement (20% and 40%) maintained the strength of both binary and ternary mortars, demonstrating statistical equivalence to the reference mortar (p > 0.05). It also contributed to an improved pore structure, reducing the migration coefficient by up to four times in the 20BLA20BCC mix (which replaces 20% of cement with BLA and 20% with BCC) compared to the reference mix. Chemically, the SCMs enhanced the chloride-binding capacity of the cementitious matrix by up to seven times in the case of the 20BCC mortar, thereby improving its durability. Therefore, all tested compositions—binary and ternary—showed mechanical and durability advantages over the reference while also contributing to the reduction in environmental impacts associated with the cement industry. Full article

Many factors and their mutual interaction between catalysts and AP/HTPB composite solid propellant induce the complexity in the combustion. Among them, we prepared two Fe-based MOFs as catalysts and investigated their catalytic effects and mechanism on the decomposition AP, HTPB and AP/HTPB complex by TG-DSC and TG-IR. The results show that both Fe-based MOFs exhibit catalytic effects on the decomposition of all samples. Specifically, in the AP/HTPB/MOFs composite system, a synergistic effect between MOFs and HTPB is observed, substantially accelerating the decomposition of both AP and HTPB, which makes the HTD temperature of AP advance approximately 100 °C, beyond what would be expected from each component acting independently. Mechanistic studies demonstrate that Fe₂O₃@C produced by the decomposition of Fe-based MOF uses the decomposition products of HTPB as a bridge to accelerate the overflow of NH₃ on the surface of AP, thereby allowing AP to decompose rapidly at a lower temperature and also accelerating the decomposition of HTPB. Moreover, its influence on the combustion performance of AP-based composite propellants was studied and the combustion rate increased by 20%. This research provides the new directions for designing and applying of Fe-based MOFs materials in HTPB-based solid propellent. Full article

Partial reduction of transition metal oxides via defect engineering is a promising strategy to enhance their electronic and photocatalytic properties. In this study, we systematically explored the mechanochemical reduction of Nb₂O₅ using LiBH₄ and NaBH₄ as reducing agents. Electron paramagnetic resonance (EPR) spectroscopy confirmed a successful partial reduction of the oxide, as seen by the presence of unpaired electrons. Interestingly, larger hydride concentrations did not necessarily enable a higher degree of reduction as large amounts of boron hydrides acted as a buffer material and thus hindered the effective transfer of mechanical energy. Powder X-ray diffraction (PXRD) and ⁷Li solid-state NMR spectroscopy indicated the intercalation of Li⁺ into the Nb₂O₅ lattice. Raman spectroscopy further revealed the increased structural disorder, while optical measurements showed a decreased band gap compared with pristine Nb₂O₅. The partially reduced samples showed significantly enhanced photocatalytic performance for methylene blue degradation relative to the unmodified oxides. Full article

Opto-spintronics is an emerging field that focuses on harnessing light to manipulate and analyze electron spins to develop next-generation electronic devices. This paper explores recent progress and the role of solid-state materials in opto-spintronics by focusing on key classes of materials, such as ferromagnetic semiconductors, two-dimensional (2D) transition metal dichalcogenides (TMDCs), and topological insulators. It examines the unique properties of ferromagnetic and antiferromagnetic materials and their ability to interact with light to affect spin dynamics, offering potential for improved sensing and quantum computing. By combining opto-spintronics with solid-state systems, spintronic devices could become faster and more efficient, leading to new technological advancements and scalable technologies. Full article

The generation of solvated electrons (SEs) from solid-state sources represents a transformative approach to driving challenging reduction reactions under ambient conditions. Diamond, with its almost unique negative electron affinity (NEA) and tunable electronic properties, is emerging as a promising candidate for SE generation in aqueous media. This perspective article reviews the current state of diamond-based SE generators and discusses their potential to catalyze sustainable nitrogen reduction (NRR) to ammonia, carbon dioxide reduction (CO₂RR), and the degradation of persistent environmental pollutants. Emphasis is placed on the fundamental processes enabling SE photoinjection from diamond to water, recent experimental breakthroughs, and the prospects for scalable, green applications. Full article

The search for effective and reliable methods of photosensitization of oxide-based semiconductor materials is of great significance for their use in photocatalytic reactions of hydrogen production and environmental remediation under natural sunlight. The present study is focused on partial substitution of titanium with manganese in the structure of layered perovskite-like titanate Na₂La₂Ti₃O₁₀, which was employed to yield a series of photocatalytically active materials, Na₂La₂Mn_xTi_3−xO₁₀ (x = 0.002–1.0), as well as their protonated forms H₂La₂Mn_xTi_3−xO₁₀ and nanosheets. It was established that the manganese cations Mn⁴⁺ are embedded in the middle sublayer of oxygen octahedra in the perovskite slabs La₂Mn_xTi_3−xO₁₀²⁻ and that the maximum achievable manganese content x in the products is ≈0.9. The partial cationic substitution in the perovskite sublattice led to a pronounced contraction of the optical band gap from 3.20 to 1.35 eV (depending on x) and, therefore, allowed the corresponding photocatalysts to utilize not only ultraviolet, but also visible and near-infrared light with wavelengths up to ≈920 nm. The materials obtained were tested as photocatalysts of hydrogen evolution from aqueous methanol, and the greatest activity in this reaction was demonstrated by the samples with low manganese contents (x = 0.002–0.01). However, the materials with greater substitution degrees may be of high interest for use in other photocatalytic processes and, especially, in thermophotocatalysis due to their improved ability to absorb the near-infrared part of solar radiation. Full article

This article discusses the superionic glassy GeS₂-Sb₂S₃-AgI system with mobile silver ions as a material for creating new energy-efficient solid-state ion emitters. The effect of replacing silver iodide with germanium sulfide on the structure of the electrolyte, activation energy of diffusion, and specific ionic conductivity was studied. Electrolytes (2.5 + x)GeS₂-27.5Sb₂S₃-(70 − x)AgI, x = 0, 5, 10, 15 were synthesized using the melt-quenching technique in evacuated quartz ampoules. The temperature dependence of conductivity and glass stability parameters (Hruby’s, Weinberg’s and Lu–Liu’s) were determined for them, and the mechanism for increasing glass-forming ability was clarified. It was shown that the presence of iodine in a germanium structural unit is more preferable than in an antimony structural unit; germanium structural units compete for iodine, reducing the number of SbI₃ crystallization centers and chain terminations, resulting in additional structural connectivity and stability. It was shown that when silver iodide was replaced by germanium sulfide, the decrease in conductivity due to the reduction in charge carriers was less than expected due to the expansion of the conduction channels. Full article