Cation Ratio Research Articles

Role of substrate and TiO2 content in TiO2:Ta2O5 coatings for gravitational wave detectors

Gravitational wave detectors (GWDs) are designed to detect the elusive signals produced by spacetime ripples, the GWs. The key to improving GWD sensitivity relies on the reduction of the thermal noise introduced by the mirrors. The high refractive index component of the high-reflectance mirrors installed in the current generation GWDs, such as Advanced LIGO and Advanced Virgo, is made of a mixture of ∼27% TiO2 and ∼73% Ta2O5. Such a coating plays a fundamental role in the GWD performance. The 27:73 TiO2:Ta2O5 ratio ensures high structural, optical, and mechanical performances, which allowed for the first ever detection of GWs, but might not be enough for new generation GWDs. Here, we investigate the potential of TiO2:Ta2O5 coatings, in a wider range of Ti/(Ta + Ti) cation ratio. Our research spans over the morphological and structural coating characteristics, and their correlation with optical and mechanical properties. On one hand, we unveil the profound influence of substrate selection and TiO2 content on the quality of coating morphology. On the other, we pinpoint the effect of TiO2 content on the structural properties of the coating, as increasing TiO2 content leads to lower temperature amorphous-to-crystalline transition, and we show that internal strain may arise due to the coexistence of TiO2 and Ta2O5 crystalline phases. Finally, substrate choice, TiO2 concentration, and crystallization characteristics emerge as pivotal factors in the pursuit of precision optics.

(Battery Division Postdoctoral Associate Research Award Sponsored by MTI Corporation and the Jiang Family Foundation) Aqueous Batteries for Grid-Scale Storage: Beyond Highly Concentrated Electrolytes

Aqueous electrolytes offer significant advantages over their organic counterparts, particularly for large-scale applications that prioritize non-flammability, scalability, and sustainability. However, the narrow electrochemical stability window of water imposes voltage limitations, resulting in low energy densities of aqueous batteries. Highly concentrated electrolytes have enabled high-voltage, mostly intercalation-type, aqueous battery chemistries, and over the past decade many additives, coatings, and highly soluble salts have been developed to manipulate the solution structure of the electrolyte and the interphasial chemistry at the electrode surfaces. However, the large amounts of specialized salts required in this approach, put into question whether GWh-scale storage is really the best application of this technology.Storage at such very large scale, however, is required for further integration of renewables and complete decarbonization of power grids. Flow batteries that decouple energy storage from power generation were developed to simplify scaling of very large batteries while maintaining cost and safety benefits of aqueous electrolytes. Here, the solubility of active materials governs the achievable energy density, which is typically an order of magnitude lower for aqueous flow batteries compared to state-of-the-art lithium-ion cells.Capitalizing on our experience with highly concentrated electrolytes and the impact of molecular symmetry and ion-pairing on electrolyte properties,1–5 we manipulate the solution structure of flow battery electrolytes to maximize active material concentration. We manipulate the hydrogen-bonding environment in the electrolyte and mediate anion-cation interactions via cation-engineering and additives, enabling more than four-fold higher concentrations for a series of metal-organic chelates and ferrocyanides than previously reported.6–8 We further developed a simple flame emission spectroscopy setup to track cation ratios in solution and study cation-dependent instabilities of presumably highly stable ferrocyanide anions.8,9 Achieving very high concentrations, however, presents a series of challenges for flow batteries. A two-molar lithium ferrocyanide electrolyte, for example, has an ionic strength comparable to a twenty-molar lithium chloride solution.8 Managing osmotic balance across the membrane thus becomes very challenging in a flow cell. Additionally, the high viscosity of concentrated electrolytes results in significant efficiency and power losses, suggesting that the “dissolve-as-much-as-possible” approach may not necessarily lead to better flow batteries.We thus studied the importance of energy density for real-world MWh-scale batteries by using satellite images to estimate the footprint of such large-scale deployments. We find that installations using lithium-ion batteries often have a comparable footprint to sodium-sulfur batteries and even demonstrator-stage flow batteries.10 This implies that low cell level energy density of flow batteries is not the key limitation of the technology, challenging the common narrative. For applications such as residential use, on the other hand, energy density certainly plays a critical role, and we discuss approaches that could enable much more compact systems.

In-situ observation of single-phase compositionally-complex oxide formation during high-pressure and high-temperature synthesis

Compositionally-complex oxides (CCOs) with equal or non-equal atomic ratios of multi-principal cations are single-phase solid solutions and possess unique structural characteristics and correlated possibilities for tailorable and exceptional functionalities. However, breakdown of single-phase structure and phase separation impair widespread adoption of CCOs under in-service environments. Here, in-situ phase transformation during high-pressure and high-temperature synthesis of an exemplary CCO (CeZrHf)0.852(YbY)0.148O2-δ is for the first time clarified by using synchrotron X-ray energy dispersive diffraction. During synthesizing at ∼4.5 GPa inside a large-volume press, ZrO2 and HfO2 gradually initiate lattice diffusion as monoclinic (022) and (220) peaks collapse and merge completely at 973 K; CeO2 starts diffusing as the dramatic intensity change of cubic (220) peak above 1073 K, causing a metastable phase formation; single-phase solid solution ultimately forms at 1673 K. The results revealed provide in-depth understanding of phase transformation dynamics and insights for novel design paradigm of CCOs.

Drip fertigation with food waste biogas effluent in a humid area is possible but challenging due to increased soil soluble sodium

To assess changes in soil salinity and salinity leaching following rainfall when food waste biogas effluent was used as a fertilizer in a humid region, a field experiment was conducted in 2020–2022 focused on broccoli drip fertigation with different percentages of biogas effluent. Five treatments consisted of 0% (CF), 25% (T25), 50% (T50), 75% (T75), and 100% (T100) biogas effluent blended with fresh water, with the same total N, P, and K. The experiment included a control (CK) that consisted of drip irrigation without fertilizer. The electrical conductivity of soil saturation paste extract (ECe), soluble sodium, sodium adsorption ratio (SAR), cation ratio of structural stability (CROSS), and broccoli yield were monitored. Drip fertigation with biogas effluent (electrical conductivity=19.0 dS/m) increased soil salinity and the ECe rose as the biogas effluent percentage increased, especially in the 0–20 cm soil profile. The T25, T50, T75, and T100 treatment ECe values were 1.2–2.2 times those of the CF treatment. Soluble sodium, SAR, and CROSS increased during the fertilization season. However, compared with CF, 25–100% biogas effluent drip fertigation did not significantly affect broccoli yield. During the post season, the soil salinity was effectively leached by rainwater. After one study year of rotation, there was almost no significant difference in ECe between treatments, but the soluble sodium, SAR, and CROSS values were significantly higher in T100 than in the CF treatment. In other words, when the total applied fresh water amount (including rainfall and irrigation) is more than 45–48 times the biogas effluent application amount (i.e., irrigation with a biogas effluent concentration of ≤75%), it may not significantly increase the soil soluble sodium. In conclusion, drip fertigation with biogas effluent can be used for broccoli fertigation in humid areas, and treatment with≤ 75% biogas effluent is suggested. Combined with the local rainfall depth, a biogas effluent application depth of ≤ 28–30 mm/year may be feasible.

Layered-Double-Hydroxide (LDH) pyroelectric nanogenerators

Layered Double Hydroxides (LDHs) have outstanding properties, including straightforward fabrication and connection of high-density arrays of aligned nanostructures on almost every (e.g., large area and flexible) substrates, high surface-to-volume ratios, biocompatibility, flame retardancy and several degrees of freedom (divalent and trivalent cations, trivalent/divalent cations ratio, intercalated anions and geometries) for tuning their properties as well as their band diagrams. Nevertheless, LDH pyroelectric devices have never been reported. Here we suggest that LDHs can be ideal building blocks for pyroelectric nanogenerators because of high gradients of both composition and energy-levels, size effects and extraordinary simplicity of fabrication and tuning. For validation, we fabricated several LDH nanoplatelets pyroelectric nanogenerators and found that, without any poling, the equivalent pyroelectric coefficients can be positive, up to 150 µC/(K*m2), or negative, down to – 160 µC/(K*m2), for nanogenerators made of ZnAl LDH or MgAl LDH nanoplatelets, respectively. Beside demonstrating extremely simple and low cost pyroelectric nanogenerators, our results suggest that LDHs are outstanding candidates for high performance pyroelectric nanodevices as, first, the areas of the fabricated devices are orders of magnitude larger than the areas of the nanoplatelet-to-metal junctions and, second, the high number of degrees of freedom of LDHs leaves room for significant improvements.

Surface optimization of double perovskite oxide La2NiFeO6 for toluene catalytic oxidation through control of cation non-stoichiometry

In recent years, perovskite oxides have gained significant attention for their potential in various heterogeneous catalysis fields, particularly in the catalytic oxidation of volatile organic compounds (VOCs). Despite this, further exploiting the potential of perovskite-based catalysts remains a major challenge. This study proposes a facile method to regulate the physical-chemical properties of double perovskite oxide La2NiFeO6 catalysts by precisely controlling the bulk A-site deficiency. The strategy enables the modulation of surface chemical environment, including the valence of surface-active sites and the distribution of oxygen species. The results reveal a volcano-like relationship between the A-site/B-site cation ratio and toluene catalytic oxidation reactivity. Sample L1.85NFO possesses superior performance for toluene catalytic oxidation with T90 at about 253 ℃, and the normalized reaction rate is twice of stoichiometric sample LNFO. Various characterizations, such as XPS, BET, SEM, and EPR were employed to study the surface properties. Surface active sites with higher oxidizability and more active oxygen species were also achieved. This work not only improves the catalytic performance of perovskite oxide at low temperatures but also contributes significantly to the practical application of low-cost perovskite oxide material in industrial settings.

Sintering, microstructure, and mechanical properties of ZrO2-doped Al2O3

ABSTRACT In the present work, the effect of Zr-doping on the sintering, microstructure development, and mechanical properties of polycrystalline Al2O3 was studied. Dopant concentrations of 830 and 2070ppm cationic ratio of Zr in Al2O3 corresponding to 2000 and 5000 wt. ppm of ZrO2 in Al2O3, respectively, were used. The sintering schedule of undoped as well as Zr-doped Al2O3 samples was optimised following a series of precoarsening experiments. The Zr-doped Al2O3 ceramics exhibited controlled grain size and improved density. Upon increasing the Zr-dopant concentration from 830 cat. ppm to 2070 cat. ppm. Zr-doped Al2O3 ceramics having a refined microstructure with a homogeneous distribution of controllably grown ZrO2 in Al2O3 matrix was obtained. Microhardness of the Zr-doped samples showed negligible dependence with Zr-doping, whereas mechanical strength was found to improve with it. The improvement in strength was attributed to the combined effect of improved sinter density, microstructural refinement, and grain-boundary strengthening.

Shielding process for the effect of anions on uranium selective recovery and heavy metal removal from simulated mine effluents

The selective separation of uranium from uranium tailing wastewater is of great importance for environmental protection and nuclear energy development. The complexation of Cl−, SO42−, NO3–, and PO43− with UO22+ seriously hindered the achievement of this goal. Herein, a process for achieving it with the coexistence of anions and cations by shielding the influence of anions was designed. Thermodynamic calculations indicated that CO32– could enhance the retention of uranium in the solution by complexing with UO22+ and capturing UO22+ in UO2SO4 and UO2HPO4 to form water-soluble uranyl-carbonate. The capturing ability of CO32– was not diminished by the increase in anion concentration. And the electrochemical experiments revealed the high efficiency of uranium electrochemical extraction in the above system. In addition, the results showed that uranium could be separated from Co2+, Cd2+, and Ni2+ ions under the coexistence of Cl−, SO42−, NO3–, and PO43−, thus achieving the selective separation of uranium in the wastewater. And the retention ratio of impurity cations in the liquid phase after separation was less than 0.003. Overall, this method provides new insights into the selective separation of uranium and heavy metal removal in real uranium tailings wastewater.

Mixed phase ZnSnN2 thin films for solar energy applications: Insight into optical and electrical properties

Zinc tin nitride (ZnSnN2, ZTN) films synthesized by magnetron co-sputtering at a temperature close to the ZTN decomposition point and with the cation ratio close to stoichiometric have been studied to gain insight into their structural, optical and electrical properties. According to X-ray diffraction and Raman spectroscopy, the samples are polycrystalline with some disorder in the cation sublattice. Hall effect measurements reveal n-type conductivity and very high carrier density above 1019 cm−3. At the lowest carrier density, the mobility achieves the best value ∼19 cm2/(V*s), which is acceptable for device applications. The optical band gap shows a blue shift with increasing electron density, which is related to the increase in tin content and the Burstein-Moss effect. Analysis of the blue shift in terms of the Burstein-Moss effect theory gives a value of 1.43 eV for the intrinsic band gap of ZTN in the mixed-phase state.

Retraction Note: The effect of changing the ratios of perovskite triple cations and anions on the optical properties and solar cell performance of perovskite thin films

Retraction Note: The effect of changing the ratios of perovskite triple cations and anions on the optical properties and solar cell performance of perovskite thin films

MgO-MgAl2O4: An Efficient Catalyst for Multicomponent Synthesis of Substituted 4H-pyran

Background: The 4H-pyran compounds are an important class of heterocyclic compounds due to their diverse biological and pharmaceutical properties. Moreover, 4H-pyran is a crucial structural component commonly encountered in the pharmaceutical industry. Thus, it has recently gained significant attention from industry researchers and academic organizations. Herein, we report an efficient and eco-friendly one-pot strategy to synthesize bioactive compounds containing 4H-pyran motifs via a multicomponent reaction. This reaction occurs by reacting equimolar amounts of ethyl acetoacetate, malononitrile, and substituted aldehyde under mild conditions in the presence of a solid catalyst, MgO-MgAl2O4. This latter, was obtained by heat treatment, at 800°C, of a layered double hydroxide with the metal cation ratio of Mg2+/Al3+ = 3:1, and it was characterized by some techniques including XRD, TG-DTA, FT-IR and N2 adsorption-desorption. Therefore, bioactive compounds containing the pyran unit may possess intriguing biological properties. The synthetic protocol offers advantages such as a simple procedure, good to excellent yields, and easy catalyst separation from the reaction mixture. Methods: Substituted 4H-pyran derivatives were prepared by the condensation reaction of substituted aldehydes, ethyl acetoacetate and malononitrile using MgO-MgAl2O4 catalyst under mild conditions. This study aims to develop an efficient methodology for synthesizing 4H-pyran heterocyclic compounds that have potential applications in biological sciences. The study utilizes MgO-MgAl2O4 as a highly effective heterogeneous catalyst. Results: The present research details the synthesis of 4H-pyran bioactive compounds using sustainable reaction conditions, which resulted in high yields and facilitated the easy separation of the catalyst from the reaction mixture. Conclusion: In summary, the MgO-MgAl2O4 spinel nanostructure has been successfully prepared and fully characterized by using different physicochemical techniques such as XRD, TG-DTA, FT-IR and N2 adsorption-desorption. Afterwards, its catalytic activity was investigated through the one-pot condensation of aryl aldehyde, malononitrile and ethyl acetoacetate. Moreover, it exhibits good catalytic activity for the synthesis of 4H-pyran derivatives under green conditions. These latter have many benefits, such as simple procedure, good to excellent yields and easy separation of the catalyst from the reaction mixture.

Efficient Optimization of High‐Quality Epitaxial Lithium Niobate Thin Films by Chemical Beam Vapor Deposition: Impact of Cationic Stoichiometry

AbstractLithium niobate is a material of special interest for its challenging functional properties, which can suit various applications. However, high quality 200‐mm LixNb1‐xO3 thin film grown on sapphire substrate have never been reported so far which limits these potential applications. This paper reports the efficient optimization of high quality LiNbO3 thin film deposition on sapphire (001) substrate through chemical beam vapor deposition in a combinatorial configuration. With this technique, flow ratio of Li/Nb can be tuned from ≈0.25 to ≈2.45 on a single wafer. Various complementary characterizations (by means of diffraction, microscopy and spectroscopy techniques) have been performed at different areas of the film (different cationic ratios) in order to investigate the impact of the cationic stoichiometry deviation on the film properties. Close to cationic stoichiometry (LiNbO3), the epitaxial films are of high quality (single phase in spite of two in‐plane domains, low mosaicity of 0.04°, low surface roughness, refractive index and band gap close to bulk values). Deviating from the stoichiometry conditions, secondary phases are detected (LiNb3O8 for Nb‐rich flow ratios, and Li3NbO4 with partial amorphization for Li‐rich flow ratios). LiNbO3 films are of high interest for various key applications in data communications among others.

Effect of exogenous application of biogenic silicon sources on growth, yield, and ionic homeostasis of maize (Zea mays L.) crops cultivated in alkaline soil

Salinity has emerged as a major threat to food security and safety around the globe. The crop production on agricultural lands is squeezing due to aridity, climate change and low quality of irrigation water. The present study investigated the effect of biogenic silicon (Si) sources including wheat straw biochar (BC-ws), cotton stick biochar (BC-cs), rice husk feedstock (RH-fs), and sugarcane bagasse (SB), on the growth of two consecutive maize (Zea mays L.) crops in alkaline calcareous soil. The application of SB increased the photosynthetic rate, transpiration rate, stomatal conductance, and internal CO2 concentration by 104, 100, 55, and 16% in maize 1 and 140, 136, 76, and 22% in maize 2 respectively. Maximum yield (g/pot) of cob, straw, and root were remained as 39.5, 110.7, and 23.6 while 39.4, 113.2, and 23.6 in maize 1 and 2 respectively with the application of SB. The concentration of phosphorus (P) in roots, shoots, and cobs was increased by 157, 173, and 78% for maize 1 while 96, 224, and 161% for maize 2 respectively over control by applying SB. The plant cationic ratios (Mg:Na, Ca:Na, K:Na) were maximum in the SB applied treatment in maize 1 and 2. The study concluded that the application of SB on the basis of soluble Si, as a biogenic source, remained the best in alleviating the salt stress and enhancing the growth of maize in rotation. The field trials will be more interesting to recommend the farmer scale.

Assessing the Impact of BaZr0.7Y0.3-YPryO3- d Composition on Water Splitting Kinetics in Composite Pr2NiO4+Δ-BaZr0.7Y0.3-YPryO3- d Electrodes in Proton-Conducting Electrolysis Cells

Protonic-ceramic electrolysis cells (PCECs), with proton-conducting oxide electrolytes, provide high current densities between 500-700°C because electrolytes such as BaCe0.8-xZrxY0.1Yb0.1O3-δ (BCZYYb) have protonic conductivities in this temperature range. The protonic conductivities of BCZYYb are almost an order of magnitude higher than oxide-ion conductivities in conventional solid-oxide electrolytes. To convert such high ionic fluxes in PCECs into efficient hydrogen production, robust positive electrodes (positrodes) must be developed with reduced overpotentials associated with water-splitting kinetics and proton incorporation [1]. The positrodes with Ruddlesden-Popper oxides like Pr2NiO4+δ(PNO) have demonstrated effective water-splitting kinetics as well as mechanical and chemical compatibility with barium zirconate electrolytes [2]. As a mixed conductor, PNO conducts polarons, oxide ions, and protonic defects (OH●) into the crystal structure [3]. However, its relatively low proton and oxide-ion conductivities limit charge transfer reaction near three-phase boundaries with the electrolyte, which increases positrode overpotentials. To improve the surface conductivity in PNO-based positrodes, our team, in collaboration with West Virginia University [4], has explored the impact of very thin overlayers of mixed ion-conducting BaZr0.7Y0.15Pr0.15O3- d (BZYP) on PNO positrode layers. Electrochemical characterization showed that the BZYP overlayers reduce the area-specific resistance of the PNO positrodes by ≈50% at 550-700°C: this suggests the extension of the electrochemically active surface area required for the water-splitting reaction beyond three-phase boundaries. The present study focuses on optimizing composite PNO-BZYP porous positrodes in conventional negatrode-supported PCECs to understand the water-splitting reaction mechanism for efficient electrolysis.Composite PNO-BaZr0.7Y0.3-yPryO3- d (BZYP) positrodes were fabricated for a range of Y/P cation ratios. The 22 mm diameter negatrode-supported button cells included 1 mm thick porous negatrodes of BaCe0.4Zr0.4Y0.1Yb0.1O3-δ(BCZYYb4411)-NiO and a spray-coated 5-10 μm thick BCZYYb4411 electrolytes as shown in figure 1. These negatrode-electrolytes were sintered at 1550°C for 6 h. The PNO and BZYP positrode powders were synthesized by solid-state reaction at 1350°C and 1500°C, respectively. PNO was identified as an orthorhombic crystal structure, and BZYP as a tetragonal crystal structure. Reactivity tests PNO and BZYP (1:1 wt ratio) at 1050°C, 1150°C, and 1250°C for 5 h showed no phase change. After negatrode-electrolyte sintering, both single-phase PNO (reference), and composite PNO-BZYP slurries were painted on the exposed electrolyte layers and sintered at 1150°C for 5 h to provide porous positrodes.Electrochemical impedance spectroscopy (EIS) and current-voltage measurements on BZYP-PNO positrode were compared with PNO positrode in the temperature range of 550-700°C. During these measurements, steam, and oxygen partial pressures were varied by 3-50%. EIS measurements informed the resistances associated with the different processes in the water-splitting reaction mechanism. The impact of both proton/oxygen ion and electron conductivity on the water-splitting kinetics could be identified based on different BZYP compositions by investigating the effects of temperatures, steam, and oxygen partial pressures. Different Y/P cation ratios in BZYP supported the investigation of how different (proton/oxygen ion and electron) conductivities in the BZYP impact the electrochemical water-splitting reaction. Figure 1

Water-soluble inorganic ions (WSIs) in the aerosols from Central Asia via transboundary transport measured in Jimunai in 2020.

Air pollution is a global issue that often transcends national borders, leading to disputes over environmental concerns and climate-mitigation responsibilities. Between March and July 2020, we collected aerosol samples in Jimunai, a town in western China neighboring Kazakhstan, to assess transboundary air pollution in the region. Our analysis focused on major water-soluble inorganic ions (WSIs), with Ca2+ and SO42- accounting for almost 60% of the total ion loading. The ratio of cations to anions was greater than one (1.33 ± 0.27), indicating alkaline aerosols during the sampling period. Our results suggest that the pollutants measured were primarily sourced from Kazakhstan, as demonstrated by local meteorological data, air-mass trajectory analysis, and pollutant emission inventories in Kazakhstan. Correlation and primary component analysis indicated that NH4+ played an important role in neutralizing NO3- and SO42-, while Cl- was significantly depleted by the probable reaction HNO3↑ + NaCl = HCl↑ + NaNO3. These findings highlight the need for continued monitoring and regulation of air pollution sources in the region to address transboundary air pollution.

Phase structure of high-entropy pyrochlore oxides: From powder synthesis to ceramic sintering

High-entropy pyrochlore ceramics have received significant attention in the field of nuclear materials due to their ability to immobilize radioactive waste. In this study, a range of medium and high-entropy Ti-based pyrochlore powders were synthesized by a two-step method. Interestingly, a monoclinic phase was observed in some powders. An innovative experiment was conducted to adjust the cation ratio at the A site, which revealed that certain cations with larger ionic radii exhibit low solid solubility in the pyrochlore lattice, resulting in the formation of the monoclinic structure. To avoid the formation of monoclinic phase, the crystal structure was adjusted by introducing Zr4+ at the B site. Based on the selection of single-phase powders, high-density pyrochlore ceramic bulks with uniform distribution of elements were prepared by spark plasma sintering. Here (Sm1/5Yb1/5Gd1/5Er1/5Dy1/5)2Ti2O7 bulks exhibited the smallest grain size at approximately 2.48 µm among all sintered samples and demonstrated a hardness of around 10.14 GPa.

Chiral Cation Doping for Modulating Structural Symmetry of 2D Perovskites.

Cation mixing in two-dimensional (2D) hybrid organic-inorganic perovskite (HOIP) structures represents an important degree of freedom for modifying organic templating effects and tailoring inorganic structures. However, the limited number of known cation-mixed 2D HOIP systems generally employ a 1:1 cation ratio for stabilizing the 2D perovskite structure. Here, we demonstrate a chiral-chiral mixed-cation system wherein a controlled small amount (<10%) of chiral cation S-2-MeBA (S-2-MeBA = (S)-(-)-2-methylbutylammonium) can be doped into (S-BrMBA)2PbI4 (S-BrMBA = (S)-(-)-4-bromo-α-methylbenzylammonium), modulating the structural symmetry from a higher symmetry (C2) to the lowest symmetry state (P1). This structural change occurs when the concentration of S-2-MeBA, measured by solution nuclear magnetic resonance, exceeds a critical level─specifically, for 1.4 ± 0.6%, the structure remains as C2, whereas 3.9 ± 1.4% substitution induces the structure change to P1 (this structure is stable to ∼7% substitution). Atomic occupancy analysis suggests that one specific S-BrMBA cation site is preferentially substituted by S-2-MeBA in the unit cell. Density functional theory calculations indicate that the spin splitting along different k-paths can be modulated by cation doping. A true circular dichroism band at the exciton energy of the 3.9% doping phase shows polarity inversion and a ∼45 meV blue shift of the Cotton-effect-type line-shape relative to (S-BrMBA)2PbI4. A trend toward suppressed melting temperature with higher doping concentration is also noted. The chiral cation doping system and the associated doping-concentration-induced structural transition provide a material design strategy for modulating and enhancing those emergent properties that are sensitive to different types of symmetry breaking.

Corrosion Resistance Enhancement of Selective Laser Melted Cost‐Effective Interstitial Medium‐Entropy Alloy via Deep Cryogenic Treatment

An economically interstitial FeMnCrNiCu medium‐entropy alloy (MEA), which exhibits preferable corrosion resistance in 3.5 wt% NaCl solution, is fabricated by selective laser melting (SLM). Compared with annealing, which is one of the posttreatments for additive manufacturing, deep cryogenic treatment (DCT) also contributes significantly to the alloy properties and is expected to improve corrosion resistance. Herein, the corrosion behavior of SLM‐MEA after DCT in 3.5 wt% NaCl solution is investigated. DCT improves corrosion resistance by promoting the uniform distribution of precipitates in SLM‐MEA and changing the cation ratio in the passive film. After DCT, the corrosion current density of the SLM‐MEA in original and annealed state decreases by 27.07% and 62.69%, respectively. The annealed SLM‐MEA exhibits the worst corrosion resistance as a result of the precipitation of continuous Cr‐rich M23C6 carbides at grain boundaries. The face‐centered cubic structure of MEA does not change after annealing or DCT. Significantly, the number, size, and distribution of the precipitates are greatly affected. DCT after annealing promotes the uniform diffuse distribution of M23C6 carbides and nanoscale Cu‐rich particles while increasing the Cr+Ni/Fe+Mn ratio in the passive film, resulting in a significant improvement in corrosion resistance.

Lithium enrichment processes in sedimentary formation waters

Reservoirs exploited for oil, gas, or geothermal energy in sedimentary basins may represent an alternative lithium resource to salars and hard rocks. Similarities in the geochemical characteristics of the basins were searched using a database of 2400 water analyses available from more than 40 sedimentary basins worldwide, notably a selection of representative geochemical trends on 13 basins. The objective was to understand better the factors controlling Li concentrations and the potentiality of such basins for the Li-recovery. Considering LiCl and MgCl relationships, major cation (Na/K, Na/Ca) and halogen (Cl/Br) ratios, Li concentrations are monitored in several basins by mixing processes between low salinity recharge waters, seawater and brines. Lithium concentrations span three orders of magnitude in brines between evaporated seawater that has passed saturation with halite and a particularly Li-enriched pole. In the latter, significant Li-enrichment is obtained when brines are primary, in equilibrium with halite, and then enriched in Li through fluid-rock interaction processes. Li-rich lithologies such as volcanic rocks, Li-enriched clay formations, or Li-phyllosilicates dispersed in siliciclastic rocks or the underlying crystalline basement probably act as the primary Li sources. Finally, Li extraction is promoted by the rise in temperature, which explains the high Li concentrations in the waters of geothermal systems. Therefore, favourable reservoirs for Li-rich brines are characterised by a brine collection from evaporites during tectonic events, such as compressive events or salt tectonics, at a relatively short distance from the present reservoir. They must be preserved from convection and surface water ingress via recharge zones to prevent dilution and Li depletion.

Improving Production Yield and Nutritional Quality of Coastal Glehnia Using Developed Hydroponic Nutrient Solution in Controlled Environment Agriculture

This study was conducted to develop a nutrient solution for coastal glehnia, evaluate the performance of the newly developed nutrient solution, and determine an adequate electrical conductivity (EC) level for growth and bioactive compounds production in controlled environment agriculture (CEA). Coastal glehnia plants cultivated in Hoagland nutrient solution with EC 1, 2, 3, 4, and 5 dS·m−1 for 20 weeks had the same ratio of cations and anions in terms of macro essential elements. Based on the ratio, a new nutrient solution for coastal glehnia was developed. Subsequently, seedlings with two main leaves were grown in Hoagland nutrient solution (H1 and H2; EC 1 and 2 dS·m−1) or a newly developed nutrient solution (N1–5; EC 1–5 dS·m−1) for 23 weeks (about 6 months), and the leaves were harvested every 5 weeks. The N1 treatment resulted in significantly higher accumulated and average shoot fresh and dry weights than in the H1 and H2 treatments. In addition, the total phenolic content and antioxidant capacity per shoot were the highest under the N1 treatment. Individual bioactive compounds, such as xanthotoxin, bergapten, and imperatorin, levels per shoot with the N1 treatment were significantly higher than those with the H1 and H2 treatments. These results demonstrate that the newly developed nutrient solution of EC 1 dS·m−1 increases the biomass and bioactive compound levels of coastal glehnia and is suitable for cultivating coastal glehnia in CEA, such as vertical farms and greenhouses.