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Considering the strong built-in electric field caused by polarization in wurtzite nitride heterostructures, the energy levels and wave functions of the two-dimensional electrons in AlyGa1−yN back-barrier Al2O3/InxAl1−xN/GaN heterostructures are calculated using the finite element difference method. The dispersion relations and electrostatic potentials of optical phonons are obtained by the transfer matrix method. The electron mobility under optical phonon scattering is studied based on the theory of Lei–Ting force balance equation. The influences of AlyGa1−yN back barrier, ternary mixed crystal effect, and size effect are also analyzed by comparing with the Al2O3/InxAl1−xN/GaN heterostructure without back barrier. It is found that the introduction of a back barrier can attenuate the effect of gate-insulating layer, but enhance the effect of barrier and channel layers on electronic states. Then, the interaction between electrons and optical phonons is weakened, so the electron mobility in AlyGa1−yN back-barrier Al2O3/InxAl1−xN/GaN heterostructure is higher than that in Al2O3/InxAl1−xN/GaN structure under the same conditions. It is also found that using a thinner AlyGa1−yN film with y = 0.25 as the back-barrier layer of Al2O3/InxAl1−xN/GaN heterostructure is more conducive to improving 2DEG mobility. These conclusions can provide references for the preparation of InxAl1−xN/GaN heterojunction devices. [ABSTRACT FROM AUTHOR]

A first-principles-based lattice model is applied to investigate the ordered phases of mixed group-III nitride ternary alloys. The model surveys the atomistic configurations with the lowest formation enthalpy for a wide range of compositions. We found novel ordered phases in wurtzite structures having specific compositions of three- and four-sevenths molar fractions of group-III cations. The configurations of group–III atoms on cation sites in those phases consist of a characteristic fragment of the ordered phases of one-third and one-half ordered phases that were previously reported. The simulation results indicate that group-III cations in ternary nitrides follow spatial positioning "atomistic distancing rules" that can be described by the pairwise interaction energy of group-III cations to realize the stabilities of the ordered structures. To minimize the formation enthalpy of a mixed crystal, the minor B, Al, Ga, and In atoms on cation sites remain neither too close to nor too distant from each other, allowing those ordered phases to be realized. [ABSTRACT FROM AUTHOR]

Photochemical valence bond isomerization of a crystalline Dewar benzene (DB) diacid monoanion salt with an acetophenone-linked piperazinium cation that serves as an intramolecular triplet energy sensitizer (DB-AcPh-Pz) exhibits a quantum chain reaction with as many as 450 product molecules per photon absorbed (Φ ≈ 450). By contrast, isomorphous crystals of the DB diacid monosalt of an ethylbenzene-linked piperazinium (DB-EtPh-Pz) lacking a triplet sensitizer showed a less impressive quantum yield of ca. Φ ≈ 22. To establish the critical importance of a triplet excited state carrier in the adiabatic photochemical reaction we prepared mixed crystals with DB-AcPh-Pz as a dilute triplet sensitizer guest in crystals of DB-EtPh-Pz. As expected from their high structural similarities, solid solutions were easily formed with the triplet sensitizer salt in the range of 0.1 to 10%. Experiments carried out under conditions where light is absorbed by the triplet sensitizer-linked DB-AcPh-Pz can be used to initiate a triplet state adiabatic reaction from 3DB-AcPh-Pz to 3HB*-AcPh-Pz, which can serve as a chain carrier and transfer energy to an unreacted DB-EtPh-Pz where exciton delocalization in the crystalline solid solution can help carry out an efficient energy transfer and enable a quantum chain employing the photoproduct as a triplet chain carrier. Excitation of mixed crystals with as little as 0.1% triplet sensitizer resulted in an extraordinarily high quantum yield Φ ≈ 517.

The (1-x)Ba 0.94 Ce 0.04 TiO 3 -xBi(In 1/2 (Li 0.5 Ta 0.5) 1/2)O 3 (BCT-BILT) relaxor ferroelectric ceramic system was explored based on the A-site vacancy design and defect dipole engineering. The impacts of different doping concentrations on the phase composition, dielectric and energy storage performance of the BCT-BILT ceramics were studied and discussed in detail. The pure BCT and 0.95BCT-0.05BILT samples exhibited a mixed crystal structure of tetragonal (T) and pseudo-cubic (PC) phase, while the BCT-BILT samples with x > 0.05 possessed a cubic (C) phase, accompanied by the secondary phases of BaBi 2 Ta 2 O 9 and BaTa 2 O 6. With an increase in the BILT doping concentration, the surface morphologies of the ceramics were continuously modulated, and the dielectric loss had been reduced to 0.001 at 1 kHz, which was beneficial to improve the energy storage properties. Compared to the pure BCT, the breakdown field strength was significantly enhanced owing to the formation of Aurivillius phase BaBi 2 Ta 2 O 9 and the increased dielectric relaxation. Ultimately, the highest energy storage density of W rec = 0.7 J/cm3 and high energy conversion efficiency of η = 95 % was realized at the composition of x = 0.05 under a small electric field of 130 kV/cm. Furthermore, the good temperature stability with the Δ W rec / W rec30°C < 9 % and Δ η / η 30°C < 6.5 % was acquired for the samples with x = 0.20–0.30 in the temperature range of 30–120 °C, owing to the synergistic roles of the defect dipoles, impurities BaBi 2 Ta 2 O 9 , and polar nanoregions (PNRs). The 0.95BCT-0.05BILT ceramic obtains discharge energy density W dis of 0.35 J/cm3 and fast discharge speed t 0.9 of 312 ns at 60 kV/cm, current density C D of 255.4 A/cm2 and power density P D of 10.2 MW/cm3 at 80 kV/cm. This work is of guiding significance for designing and optimizing energy storage performance of lead-free relaxors from the perspective of defect building and engineering. [ABSTRACT FROM AUTHOR]

In this investigation, we employ density functional theory with the generalized gradient approximation of Wu–Cohen and the modified Beck–Johnson approach. Our focus is on examining the structural, electronic and thermodynamic properties of ternary chalcopyrite CdXP2 (X: Si and Sn) compounds. Our computed results of ternary structures for structural properties, for instance, tetragonal distortion, equilibrium lattice constants and bond lengths, show good agreement with the available results of the experimental and theoretical calculations. Our calculated positive results of cohesive energy and negative values of the formation energies of the title materials show their thermodynamic stability as well as highlight their possible experimental fabrication at these concentrations. From band structure calculations, it is found that the energy bandgap is of direct nature at Γ–Γ symmetry points for both ternary and quaternary alloys; however, the width of the bandgap is found to be decreased with increasing Sn concentration in the CdSi1–xSnxP2 alloys. Moreover, thermodynamic properties using the quasi-harmonic Debye model are also computed. Our study provides a platform for further experimental and theoretical investigations to expose the potential of these materials for their applications. [ABSTRACT FROM AUTHOR]

In this investigation, we employ density functional theory with the generalized gradient approximation of Wu–Cohen and the modified Beck–Johnson approach. Our focus is on examining the structural, electronic and thermodynamic properties of ternary chalcopyrite CdXP2 (X: Si and Sn) compounds. Our computed results of ternary structures for structural properties, for instance, tetragonal distortion, equilibrium lattice constants and bond lengths, show good agreement with the available results of the experimental and theoretical calculations. Our calculated positive results of cohesive energy and negative values of the formation energies of the title materials show their thermodynamic stability as well as highlight their possible experimental fabrication at these concentrations. From band structure calculations, it is found that the energy bandgap is of direct nature at Γ–Γ symmetry points for both ternary and quaternary alloys; however, the width of the bandgap is found to be decreased with increasing Sn concentration in the CdSi1–xSnxP2 alloys. Moreover, thermodynamic properties using the quasi-harmonic Debye model are also computed. Our study provides a platform for further experimental and theoretical investigations to expose the potential of these materials for their applications. [ABSTRACT FROM AUTHOR]

The excavation of ivory and other artifacts from the Sanxingdui Ruins holds profound research significance in tracing of both the ancient Shu and Chinese civilizations. After being unearthed, a large quantity of ivory encountered issues such as dehydration, pulverization, and cracking, resulting from poor preservation conditions. To establish effective long-term conservation strategies for the excavated ivory, this paper takes the dentin of excavated ivory from the No.7 Sacrificial Pit (K7) at the Sanxingdui Ruins as the research object, focusing on the primary correlation between its microscopic porous structure and moisture states. The results show that the organic collagen protein component of the excavated ivory has already undergone basically diagenetic degradation. The remaining main mineral phases are hydroxyapatite and carbonated hydroxyapatite, exhibiting a mixed crystal structure with mainly needle-like and secondary lamellar. The porosity of the excavated ivory, as measured by dry and wet methods, is approximately 62 and 60%, respectively. The pore size distributions are primarily concentrated in the ranges of 5–100 nm for the dry method and 10–200 nm for the wet method. These diverse and heterogeneous pore structures store approximately 35–38% of water as free water and adsorbed water. Free water is primarily found in dentinal tubules, interlayer gaps and cracks, providing volume support and stabilizing equilibrium with the external environment. Adsorbed water is mainly present in the pores (d < 100 nm), providing support function through intermolecular forces and hydrogen bonding. The deterioration of excavated ivory is positively correlated with the loss of moisture. This is due to irreversible structural damage caused by the loss of water's supportive, bonding, and stabilizing effects. Among them, the rapid migration and evaporation of free water affect the expansion of cracks and the formation of new fissures. This study offer a robust scientific basis and valuable insights for the subsequent conservation of excavated ivory, and also provide guidance for the research of other fragile bone and horn relics. [ABSTRACT FROM AUTHOR]

In China, groundwater loss caused by underground coal mining is becoming increasingly serious. The key to groundwater restoration is to repair mining-induced water-conducting fractures (WCFs) in the overlying strata. In this study, the adsorption–consolidation sealing characteristics of chemical precipitates were used to conduct permeability reduction (PR) experiments, including adding mixed CaCO3 and Fe(OH)3 to a sandstone specimen with a single fracture at room temperature. An aqueous solution of Na2CO3 was used as the simulated groundwater, and a solution of mixed CaCl2 and FeCl2 was used as the repair reagent to simulate the water seepage conditions of a fractured rock mass. The two aqueous solutions were simultaneously injected into a single-fractured rock specimen at a constant flow rate. The experimental results show that the Fe(OH)3 colloid encapsulated CaCO3 crystals in a mixed precipitate, reducing the overall structural stability of the mixed precipitate and restricting repair and PR efficiency. However, the Fe(OH)3 precipitate had better PR efficiency in the initial stage of the experiment. Therefore, a better scheme was put forward to repair the WCF, utilizing a mixed Fe(OH)3 and CaCO3 precipitate with a molar ratio close to 1:4 in the early stage and a single CaCO3 precipitate in the later stage. [ABSTRACT FROM AUTHOR]

X-ray diffraction (XRD) is one of the most essential techniques for characterizing various crystals. However, when nanocrystals are present, the diffraction peaks become significantly broadened and reduced in intensity, making phase and microstructure analysis challenging. To obtain more refined microstructural information from nanocrystals, various methods have been developed to enhance diffraction peaks, with step scanning being a commonly used approach. Additionally, increasing instrument broadening (IB) by adjusting slit sizes to enlarge the irradiation area is a convenient yet often overlooked method. In this study, the effects of IB on the diffraction peak intensities of nanocrystals and micron crystals in mixed materials were thoroughly investigated. The results show that the intensities of both nanocrystals and micron crystals increase as IB increases, a behavior similar to that observed when extending the testing time during step scanning. However, the rate of increase in peak heights for nanocrystals is higher than for micron crystals, while the rate of increase in peak width for nanocrystals is lower, which is a significant departure from the effects seen in step scanning. In other words, nanocrystal peaks become sharper and more distinct as IB increases. This phenomenon is explained by the different components of peak width for nanocrystals and micron crystals, based on Lorentz mathematical model analysis. Based on these findings, it is recommended to utilize larger IBs in combination with step scanning to further reinforce nanocrystal peaks in mixed materials. [ABSTRACT FROM AUTHOR]

Pharmaceutical solid solutions are gaining increased interest as alternatives to salts and co-crystals for the enhancement of drug solubility and dissolution kinetics. Industrially, they are also responsible for the entrapment of potentially toxic impurities in drug substances. The accidental incorporation of process impurities into the lattice of a growing crystal, or the intentional incorporation of an additive, can vastly alter the product's properties. Reported effects include solubility enhancements, changes in melting point, shifting polymorph stabilities, growth inhibition, and change in crystal habit, among others. This work combines the fields of impurity rejection, solid solutions, and dyeing crystals, to provide visual evidence of those effects, and to further demonstrate how impure regions in a single crystal can present vastly different behaviors to the purified regions of the same crystal. The work revolves around four model host–guest pairs, two of them previously unreported. These include mixed crystals of acetaminophen with curcumin, sulforhodamine B, and acid fuchsin, as well as potassium sulfate dyed with acid fuchsin. Results challenge common assumptions in the study of multicomponent crystals, demonstrating how neglecting composition anisotropy may lead to misdiagnosing solid solutions as surface adsorbed impurities in impurity retention diagnostics, and how neglecting the habit-modifying effects of dissolved impurities may lead to the use of erroneous models for growth inhibition. At the same time, we present opportunities for the development of novel impurity rejection and crystal engineering strategies, aiding the growth of anisotropic crystals with properties that can be fine-tuned in continuum. [ABSTRACT FROM AUTHOR]

Lithium niobate and lithium tantalate are among the most widespread materials for nonlinear, integrated photonics. Mixed crystals with arbitrary Nb–Ta ratios provide an additional degree of freedom to not only tune materials properties, such as the birefringence but also leverage the advantages of the singular compounds, for example, by combining the thermal stability of lithium tantalate with the larger nonlinear or piezoelectric constants of lithium niobate. Periodic poling allows to achieve phase-matching independent of waveguide geometry and is, therefore, one of the commonly used methods in integrated nonlinear optics. For mixed crystals, periodic poling has been challenging so far due to the lack of homogeneous, mono-domain crystals, which severely inhibit domain growth and nucleation. In this work, we investigate surface-near (< 1 μ m depth) domain inversion on x-cut lithium niobate tantalate mixed crystals via electric field poling and lithographically structured electrodes. We find that naturally occurring head-to-head or tail-to-tail domain walls in the as-grown crystal inhibit domain inversion at a larger scale. However, periodic poling is possible if the gap size between the poling electrodes is of the same order of magnitude or smaller than the average size of naturally occurring domains. This work provides the basis for the nonlinear optical application of lithium niobate tantalate mixed crystals. [ABSTRACT FROM AUTHOR]

Low‐dimensional metal halide perovskites exhibit exceptional photoelectronic properties and intrinsic stability, positioning them as a promising class of semiconductor materials for light‐emitting devices and photodetectors. In this work, we present a millimeter‐scale single crystal of mixed low‐dimensional (one‐dimensional–zero‐dimensional [1D–0D]) organic lead iodide with well‐defined crystallinity. The fabricated single‐crystal devices demonstrate high‐sensitivity photoresponse and x‐ray detection performance. By spatially isolating organic molecules to form the mixed 1D–0D crystal structure, ion migrations is effectively suppressed, resulting in a remarkable three orders of magnitude reduction in the dark current (56.4 pA @200 V) of the single‐crystal devices. Furthermore, by enhancing the background characteristics, we achieved an impressive low x‐ray detection limit of 154.5 nGys−1 in the single‐crystal device. These findings highlight that the mixed 1D–0D organic lead iodide configuration efficiently controls ion migration within the crystal structure, offering a promising avenue for realizing high‐performance perovskite‐based photodetectors and x‐ray detectors. [ABSTRACT FROM AUTHOR]

Interfacial electronic structure modulation of nickel‐based electrocatalysts is significant in boosting energy‐conversion‐relevant urea oxidation reaction (UOR). Herein, porous carbon nanofibers confined mixed Ni‐based crystal phases of Ni2P and NiF2 are developed via fluorination and phosphorization of Ni coated carbon nanofiber (Ni2P/NiF2/PCNF), which possess sufficient mesoporous and optimized Gibbs adsorption free energy by mixed phase‐induced charge redistribution. This novel system further reduces the reaction energy barrier and improves the reaction activity by addressing the challenges of low intrinsic activity, difficulty in active site formation, and insufficient synergism. A considerably high current density of 254.29 mA cm−2 is reached at 1.54 V versus reversible hydrogen electrode on a glass carbon electrode, and the cell voltage requires 1.39 V to get 10 mA cm−2 in hydrogen generation, with very good stability, about 190 mV less than that of the traditional water electrolysis. The facile active phase formation and high charge transfer ability induced by asymmetric charge redistribution are found in the interface, where the urea molecules tend to bond with Ni atoms on the surface of heterojunction, and the rate‐determining step is changed from CO2 desorption to the fourth H‐atom deprotonation. The work reveals a novel catalyst system by interfacial charge redistribution induced by high bond polarity for energy‐relevant catalysis reactions. [ABSTRACT FROM AUTHOR]

The laser cladding NiFeCrCoMo high entropy alloy coatings (HEACs) were prepared on the surface of TP347H steel. The microstructure, phase formation, microhardness, and electrochemical corrosion performance were investigated. The result shows that the coating exhibits a single FCC structure, with a cross-sectional structure composed of matrix, heat-affected-zone (HAZ), fusion-zone (Fz), and HEA-coating-zone (HEACz). The Fz structure is a mixed crystal structure with dense columnar crystals and equiaxed crystals. The HEACz and surface of the coating are both composed of dendritic structures. Mo is enriched within the dendrites. The average hardness of the coating is 455.75 HV1.0, which is approximately 2.26 times that of TP347 steel. The thermodynamic parameters of the HEA coating include the following: ΔHmix = − 10.28 kJ/mol, ΔSmix = 15.07 J/kmol, δ = 8.46%, Ω = 2.19, meeting the conditions for the formation of a single FCC stable solid solution in a multiprincipal component high entropy alloy under nonequilibrium solidification conditions. Compared with TP347H steel, the Tafel curve capacitance arc radius of HEACs is much larger than the former in 3.5% NaCl solution, with higher Ecorr, lower Icorr, and larger |Z|, Rs, Rf, and Rct, exhibiting better electro-chemical corrosion performance, which can be attributed to the comprehensive effect of the passivation film as a single FCC solid solution phase. [ABSTRACT FROM AUTHOR]

This study was intended to investigate the mechanical property and cutting performance of AlTiBN coating for machining of exotic materials such as heat-resistant alloys and Titanium alloys, which has been increasing for aerospace, energy and medical industries. In conventional PVD coatings for cutting tools, Cr and Si has often been added to AlTiN in order to increase hardness and heat resistance, achieving high wear resistance. However, these methods increase hardness as well as Young's modulus, which reduces toughness of coating. In exotic materials milling, coatings with a high Young's modulus tends to develop internal cracks, leading to early destruction of the coatings. In this research, optimizing B content of AlTiBN coating, we realized low Young's modulus while maintaining high hardness. This is probably because the pure AlTiN changed to a mixed crystal structure of cubic and hexagonal by the addition of B. When the cutting performance of this AlTiBN coating was evaluated in milling for Inconel 718, it was found that internal cracks were suppressed at the initial stage of processing. As a result, cemented carbide tool with the AlTiBN coating achieved approximately 1.6 times longer tool life than that with B-free AlTiN coating. [ABSTRACT FROM AUTHOR]

In mixed crystals, two or more elements exhibit comparable properties and can be substituted freely. As a special type of "substitutional doping," the properties of materials can be adjusted by altering the doping ratio of elements. Mixed-vanadate crystal Lu x Gd 1-x VO 4 is a promising laser host material with excellent chemical stability, mechanical property and thermal conductivity. The substitutional doping ratio of the two rare-earth elements determines the value of x. The thermal, optical, and laser properties of the material vary with x. However, the two types of atoms showing little difference in the same location in mixed crystals form substitutional solid solutions with alike atomic radii as well as electronic structures. Therefore, distinguishing comparable elements in mixed crystals at the atomic scale and quantitatively analyzing the doping ratio in mixed crystals are challenging. In this study, combining high-angle annular dark field (HAADF) and electron energy-loss spectroscopy (EELS), we accurately characterize the atomic structure of mixed-vanadate single crystal Lu x Gd 1-x VO 4 along the [111] orientation as well as the distribution of two rare-earth elements at the atomic scale. The ratio of Lu and Gd and the doping rules in the crystals are quantitatively analyzed. In addition, combined with the energy dispersive X-ray spectroscopy (EDS) results of the [100] crystal orientation, a uniform random distribution of Lu and Gd in the Lu x Gd 1-x VO 4 crystal is confirmed. This study provides a new means of understanding mixed-crystal structures and solves the problem of quantitative analysis of elemental doping in materials at the atomic scale, thus laying the foundation for exploring the relationships among composition, structure, and function in materials. [Display omitted] [ABSTRACT FROM AUTHOR]

Aqueous lithium‐ion batteries (ALIBs) have attracted extensive interest since the safety problems of traditional lithium‐ion batteries are waived. Although the energy density of ALIBs is improved, their rate capability and power density are still poor due to the slow Li+ diffusivity of the existing anode materials, and their cyclic stability is also poor. Here, W7Nb4O31 nanorods with very fast‐ and stable‐charging capability are explored as a new anode material for ALIBs for the first time. This material owns different tetragonal tungsten bronze (TTB) structures together with 4 × 4 ReO3‐type blocks confined by TTB matrices, allowing abundant pentagonal and quadrangular tunnels for Li+ transport. These large‐sized tunnels combine with the large interlayer spacing (≈3.95 Å) not only lead to extremely fast Li+ diffusivity but also small unit‐cell volume variations (maximum 2.1%) during lithiation/delithiation, thereby enabling the LiMn2O4//W7Nb4O31 full cell to possess excellent rate capability with a 50C versus 1C capacity ratio of 68.3%, ultrahigh power density of 9854 W kg–1, and superior cyclic stability with capacity retention of 89.7/66.7/72.0% at 1C/5C/50C over 1000/10 000/10 000 cycles. This comprehensive study demonstrates that the W7Nb4O31 nanorods are highly promising for fast‐ and stable‐charging ALIBs. [ABSTRACT FROM AUTHOR]

The growing market of printed electronics requires the development of new materials and processing technologies that enable the design of smart wearables, integrated sensors, and next-generation electronics. Against the backdrop of increasing material scarcity, these approaches must be resource-conserving and, at the same time, competitive with conventional technologies. As an alternative to nanoparticle-based inks currently used in printed electronics, another technology has been emerging in the last years that utilizes metal organic decomposition (MOD) inks, which are easy to fabricate and have a long shelf life. In this study, a method is presented that allows the direct formation of thin copper-nickel alloy films from a MOD ink. These alloys are preferably used for sensors like strain gauges as they exhibit a low thermal coefficient of resistivity (TCR). 250 nm thin alloy films are coated on glass substrates and thermally functionalized. In a conventional hot plate heat treatment under a nitrogen atmosphere, 10.2% bulk conductivity for a Cu55Ni45 alloy with a TCR of 8.3 × 10−5 K−1 is reached. X-ray diffraction analysis indicates the formation of a mixed crystal composed of nickel and copper atoms. A laser-based functionalization process is developed that allows the processing of Cu55Ni45 alloy films under ambient conditions without the formation of copper or nickel oxides. Laser-functionalized films exhibit 5.3% of the conductivity of bulk material. This study shows that metal alloy films can be fabricated directly from amine-based MOD inks. [ABSTRACT FROM AUTHOR]

Defects dictate the properties of many functional materials. To understand the behaviour of defects and their impact on physical properties, it is necessary to identify the most stable defect geometries. However, global structure searching is computationally challenging for high-throughput defect studies or materials with complex defect landscapes, like alloys or disordered solids. Here, we tackle this limitation by harnessing a machine-learning surrogate model to qualitatively explore the structural landscape of neutral point defects. By learning defect motifs in a family of related metal chalcogenide and mixed anion crystals, the model successfully predicts favourable reconstructions for unseen defects in unseen compositions for 90% of cases, thereby reducing the number of first-principles calculations by 73%. Using CdSexTe1−x alloys as an exemplar, we train a model on the end member compositions and apply it to find the stable geometries of all inequivalent vacancies for a range of mixing concentrations, thus enabling more accurate and faster defect studies for configurationally complex systems. [ABSTRACT FROM AUTHOR]

We showcase herein organic crystalline solid solutions (CSSs) based on the simplest polycyclic aromatic hydrocarbon (PAH) scaffold, naphthalene, stabilized by dispersion forces induced by adamantane substitution. High thermal stability of the host and guest molecules synthesized by cross‐coupling of dibromonaphthalene derivatives and 4‐(1‐adamantyl)phenyl boronic ester enabled formation of crystals by sublimation. We could generate binary monocrystalline solid solution systems proven by X‐ray crystallography, the first system of designed CSSs stabilized exclusively via dispersion forces with structural evidence. These observations are additionally supported by lattice energy calculations and spectroscopic examinations. For the generation of CSSs, it is of utmost importance that the host and guest molecules have similar lattice energies and spatial compatibility. We anticipate that the thermostable organic CSS design demonstrated herein would be beneficial for functional materials and further investigation towards materials with unique properties. [ABSTRACT FROM AUTHOR]

Coarse colorless single crystals of lithium lutetium bis[orthomolybdate(VI)], LiLu[MoO4]2, were obtained as a by-product from a reaction aimed at lithium derivatives of lutetium molybdate. The title compound crystallizes in the scheelite structure type (tetragonal, space group I41/a) with two formula units per unit cell. The Wyckoff position 4b (site symmetry ...) comprises a mixed occupancy of Li+ and Lu3+ cations in a 1:1 ratio. In comparison with a previous powder X-ray study [Cheng et al. (2015). Dalton Trans. 44, 18078–18089.] all atoms were refined with anisotropic displacement parameters. [ABSTRACT FROM AUTHOR]

Coarse colorless single crystals of lithium lutetium bis[orthomolybdate(VI)], LiLu[MoO4]2, were obtained as a by-product from a reaction aimed at lithium derivatives of lutetium molybdate. The title compound crystallizes in the scheelite structure type (tetragonal, space group I41/a) with two formula units per unit cell. The Wyckoff position 4b (site symmetry ...) comprises a mixed occupancy of Li+ and Lu3+ cations in a 1:1 ratio. In comparison with a previous powder X-ray study [Cheng et al. (2015). Dalton Trans. 44, 18078–18089.] all atoms were refined with anisotropic displacement parameters. [ABSTRACT FROM AUTHOR]

To generate reliable climate predictions, global models need accurate estimates of all the energy fluxes contributing to the Earth's radiation budget (ERB). Clouds in general, and more specifically ice clouds, play a key role in the determination of the ERB as they may exert either a feedback or a forcing action, depending on their optical and microphysical properties and physical state (solid/liquid). To date, accurate statistics and climatologies of cloud parameters are not available. Specifically, the ice cloud composition in terms of ice crystal shape (or habit) is one of the parameters with the largest uncertainty. The Far-infrared Outgoing Radiation Understanding and Monitoring (FORUM) experiment, foreseen to be the ninth Earth Explorer mission of the European Space Agency, will measure, for the first time spectrally resolved from space, the entire upwelling spectrum emitted by the Earth from 100 to 1600 cm -1. The far-infrared portion of the Earth spectrum, especially from 200 to 600 cm -1 , is very sensitive to cloud ice crystal shapes; thus, FORUM measurements could also represent an opportunity to study the ice cloud composition in terms of ice crystal habit mixtures. To investigate this possibility, we developed an accurate and advanced scheme allowing us to model ice cloud optical properties – also in cases of clouds composed of mixed ice crystal habits. This feature is in fact necessary because in situ measurements acquired over the years also point out that the shape of ice cloud crystals varies depending on the crystal size range. In our model, the resulting cloud optical properties are also determined by the input habit fractions. Thus, the retrieval of these fractions from spectral radiance measurements can be attempted. Using 375 different cloudy scenarios, we assess the performance of our retrieval scheme in the determination of crystal habit mixtures starting from FORUM-simulated measurements. The most relevant error components affecting the retrieved cloud parameters are not very large and are of random nature; thus, FORUM measurements will allow us to set up an accurate climatology of cloud parameters. To provide an example of the benefit that one could get from the habit mixture retrievals, we also show the improved accuracy of the thermal outgoing fluxes calculations compared to using assumed mixtures. [ABSTRACT FROM AUTHOR]

In calcium nephrolithiasis (CaNL), most calcium kidney stones are identified as calcium oxalate (CaOx) with variable amounts of calcium phosphate (CaP), where CaP is found as the core component. The nucleation of CaP could be the first step of CaP+CaOx (mixed) stone formation. High urinary supersaturation of CaP due to hypercalciuria and an elevated urine pH have been described as the two main factors in the nucleation of CaP crystals. Our previous in vivo findings (in mice) show that transient receptor potential canonical type 3 (TRPC3)-mediated Ca2+ entry triggers a transepithelial Ca2+ flux to regulate proximal tubular (PT) luminal [Ca2+], and TRPC3-knockout (KO; -/-) mice exhibited moderate hypercalciuria and microcrystal formation at the loop of Henle (LOH). Therefore, we utilized TRPC3 KO mice and exposed them to both hypercalciuric [2% calcium gluconate (CaG) treatment] and alkalineuric conditions [0.08% acetazolamide (ACZ) treatment] to generate a CaNL phenotype. Our results revealed a significant CaP and mixed crystal formation in those treated KO mice (KOT) compared to their WT counterparts (WTT). Importantly, prolonged exposure to CaG and ACZ resulted in a further increase in crystal size for both treated groups (WTT and KOT), but the KOT mice crystal sizes were markedly larger. Moreover, kidney tissue sections of the KOT mice displayed a greater CaP and mixed microcrystal formation than the kidney sections of the WTT group, specifically in the outer and inner medullary and calyceal region; thus, a higher degree of calcifications and mixed calcium lithiasis in the kidneys of the KOT group was displayed. In our effort to find the Ca2+ signaling pathophysiology of PT cells, we found that PT cells from both treated groups (WTT and KOT) elicited a larger Ca2+ entry compared to the WT counterparts because of significant inhibition by the store-operated Ca2+ entry (SOCE) inhibitor, Pyr6. In the presence of both SOCE (Pyr6) and ROCE (receptor-operated Ca2+ entry) inhibitors (Pyr10), Ca2+ entry by WTT cells was moderately inhibited, suggesting that the Ca2+ and pH levels exerted sensitivity changes in response to ROCE and SOCE. An assessment of the gene expression profiles in the PT cells of WTT and KOT mice revealed a safeguarding effect of TRPC3 against detrimental processes (calcification, fibrosis, inflammation, and apoptosis) in the presence of higher pH and hypercalciuric conditions in mice. Together, these findings show that compromise in both the ROCE and SOCE mechanisms in the absence of TRPC3 under hypercalciuric plus higher tubular pH conditions results in higher CaP and mixed crystal formation and that TRPC3 is protective against those adverse effects. [ABSTRACT FROM AUTHOR]

Perfluoride glass ceramics (FGCs) with SrF 2 /CaF 2 mixed crystals were prepared using a concurrent rapid-quenching-crystallization process. The FGCs contained dense, homogeneous, round crystals of sizes less than 1 μm with high transmittance (exceeding 80 % at 3–8 μm) and low phonon energy (508 cm−1). The fluorescence properties of the FGCs doped with Er and Dy were investigated. The energy transfer efficiency between Er and Dy reached 93.81 % and 98.13 %, corresponding to Er: 4I 11/2 to Dy: 6H 5/2 and Er: 4I 13/2 to Dy: 6H 11/2 , respectively. This enhancement is attributed to the enrichment of rare-earth ions in the crystals induced by phase-separation and low phonon energy of the host material, FGC. Moreover, the average lifetime of Er: 4I 11/2 in FGC reached 10.13 ms, which is the highest reported value for glass ceramics to our knowledge. This study enriches the research theory of FGC and provides guidance for expanding the properties of materials for mid-infrared photonics. [ABSTRACT FROM AUTHOR]

Coarse colorless single crystals of lithium lutetium bis[orthomolybdate(VI)], LiLu[MoO4]2, were obtained as a by-product from a reaction aimed at lithium derivatives of lutetium molybdate. The title compound crystallizes in the scheelite structure type (tetragonal, space group I41/a) with two formula units per unit cell. The Wyckoff position 4b (site symmetry 4) comprises a mixed occupancy of Li+ and Lu3+ cations in a 1:1 ratio. In comparison with a previous powder X-ray study [Cheng et al. (2015). Dalton Trans. 44, 18078-18089.] all atoms were refined with anisotropic displacement parameters. [ABSTRACT FROM AUTHOR]

Coarse colorless single crystals of lithium lutetium bis[orthomolybdate(VI)], LiLu[MoO4]2, were obtained as a by-product from a reaction aimed at lithium derivatives of lutetium molybdate. The title compound crystallizes in the scheelite structure type (tetragonal, space group I41/a) with two formula units per unit cell. The Wyckoff position 4b (site symmetry 4) comprises a mixed occupancy of Li+ and Lu3+ cations in a 1:1 ratio. In comparison with a previous powder X-ray study [Cheng et al. (2015). Dalton Trans. 44, 18078-18089.] all atoms were refined with anisotropic displacement parameters. [ABSTRACT FROM AUTHOR]

In addressing the global need for sustainable energy conversion, this study presents a breakthrough in thermoelectric materials research by optimizing the Bi2O2Se1–xTex system in the Bi2O2Se/Bi2O2Te pseudobinary series. Leveraging the principles of innovative transport mechanisms and defect engineering, we introduce tellurium (Te) doping into Bi2O2Se to enhance its thermoelectric properties synergistically. With the help of various advanced characterization tools such as XRD, SEM, TEM, XPS, FTIR, TGA, LFA, and DSC, combined with relevant resistance and density measurement techniques, we conducted an in-depth exploration of the complex interactions between various factors within thermoelectric materials. We recognize that the balance and synergy of these factors in the thermoelectric conversion process are crucial to achieving efficient energy conversion. Through systematic research, we are committed to revealing the mechanisms of these interactions and providing a solid scientific foundation for the optimal design and performance enhancement of thermoelectric materials. Finally, the advantage coefficient (ZT) of the thermoelectric material has been significantly improved. The crystallographic analysis confirms the formation of a continuous series of mixed crystals with varying Te concentrations, adhering to Vegard's law and exhibiting significant improvements in electrical and thermal conductivities. The Bi2O2Se1–xTex crystals, particularly the Bi2O2Se0.6Te0.4 composition, demonstrate a peak ZT of 0.86 at 373 K. This achievement aligns with recent advancements in defect-enabled mechanisms and band convergence and sets a new standard for high-performance thermoelectrics. The study's findings contribute significantly to the ongoing quest for efficient thermal-to-electrical energy conversion, offering a promising avenue for future sustainable energy technologies. [ABSTRACT FROM AUTHOR]

The treatment of the bulky Rind-based dibromosilanes, (Rind)2SiBr2 (2) [Rind = 1,1,7,7-tetra-R1-3,3,5,5-tetra-R2-s-hydrindacen-4-yl: EMind (a: R1 = Et, R2 = Me) and Eind (b: R1 = R2 = Et)], with two equivalents of tBuLi in Et2O at low temperatures resulted in the formation of blue solutions derived from the diarylsilylenes, (Rind)2Si: (3). Upon warming the solutions above −20 °C, the blue color gradually faded, accompanying the decomposition of 3 and yielding cyclic hydrosilanes (4) via intramolecular C–H bond insertion at the Si(II) center. The molecular structures of the bulky Eind-based 3b and 4b were confirmed by X-ray crystallography. Thus, at −20 °C, blue crystals were formed (Crystal-A), which were identified as mixed crystals of 3b and 4b. Additionally, colorless crystals of 4b as a singular component were isolated (Crystal-B), whose structure was also determined by an X-ray diffraction analysis. Although the isolation of 3 was difficult due to their thermally labile nature, their structural characteristics and electronic properties were discussed based on the experimental findings complemented by computational results. We also examined the hydrolysis of 3b to afford the silanol, (Eind)2SiH(OH) (5b). [ABSTRACT FROM AUTHOR]

Eddavidite is a new mineral species (IMA2018-010) with ideal formula, Cu12Pb2O15Br2, and cubic Fm 3 ¯ m symmetry: a = 9.2407(9) Å; V = 789.1(2) Å3; Z = 2. Eddavidite is the bromine analog of murdochite, Cu12Pb2O15Cl2, with which it forms a solid solution series. The type locality is the Southwest mine, Bisbee, Cochise County, Arizona, U.S.A. Eddavidite also occurs in the Ojuela mine, Mapimí, Durango, Mexico. Eddavidite occurs as domains within mixed murdochite–eddavidite crystals. The empirical formula, normalized to 12 Cu apfu, is Cu12(Pb1.92Fe0.06Si0.06)(O15.08F0.02)-(Br0.99Cl0.89☐0.12). Type locality samples contain up to 67% eddavidite component, while Ojuela mine samples contain up to 62%. Mixed eddavidite–murdochite crystals show forms {100} and {111}; the habit grades from cubic through cuboctahedral to octahedral. Mixed eddavidite–-murdochite crystals exhibit good cleavage on {111}. Eddavidite is black, opaque with submetallic luster, and visually indistinguishable from intergrown murdochite. Its Mohs hardness is 4; dmeas. = 6.33 g/cm3, dcalc. = 6.45 g/cm3. The crystal structure, refined to R = 0.0112, consists of corner-sharing square planar CuO4 units, arranged in Cu12O24 metal oxide clusters, which encapsulate Br atoms. PbO8 cubes share edges with Cu12O24 clusters in a continuous framework. Eddavidite incorporates bromine remaining after desiccation of paleo-seawater at its two known localities, which were both once situated along the Western Interior Seaway. [ABSTRACT FROM AUTHOR]

Salt precipitation on the surface of porous media significantly affects water transport processes. Most studies on salt precipitation mainly focused on single salts, but in nature, salt precipitation usually occurs as mixtures. Consequently, information on the crystallization of salt mixtures and its effect on water transport remains scarce. This study investigated the precipitation of mixtures (the mass ratios of NaCl:Na2SO4 were 3:7, 5:5, and 7:3, respectively) of NaCl (typical efflorescence) and Na2SO4 (typical subflorescence) in the initially saturated sandy soil columns and its effect on evaporation and compared it with the cases of the two salts individually. The results showed that salt mixtures exhibited a mixed pattern of crystals including both efflorescence and subflorescence, and the efflorescence showed granular aggregation, unlike the mono‐salts. The crystallization coverage of the salt mixtures was smaller than that of NaCl mono‐salt; high (7:3) and low (5:5 and 3:7) proportions of NaCl led to larger and smaller crystallization coverage than that of Na2SO4 mono‐salt, respectively. While the salt mixtures had less crystallization coverage than the mono‐salts, they showed lower evaporation because the salt mixtures formed a denser crystallization structure of efflorescence‐subflorescence‐soil layer, this crystallization structure exhibited greater inhibition of water vapour diffusion, thus reducing evaporation. In addition, the crystallization of the salt mixtures with higher NaCl proportion afforded greater resistance of evaporation. The mixed crystallization pattern formed by the salt mixtures significantly enhances the crystallization resistance to evaporation. [ABSTRACT FROM AUTHOR]

The document is a contents list for the journal CrystEngComm, which focuses on the design and understanding of solid-state and crystalline materials. It includes a mini review on zeolitic imidazolate framework derivatives as anode materials for sodium and potassium-ion batteries, as well as communications and papers on various topics such as channel confinement and separation properties in an adaptive supramolecular framework, polymorphism and orientation control of copperdicarboxylate metal-organic framework thin films, and the kinetics of crystal growth. The journal is published by The Royal Society of Chemistry, a leading chemistry community. [Extracted from the article]

Novel Raman crystals can significantly help to expand the available laser wavelength bands and effectively promote the development of laser technology. Bismuth molybdate and tungstate mixed crystals, Bi2Mo2.6W0.4O12 (BMO), with a scheelite crystal structure, are found to have superior Raman gain characteristics. Large-sized single crystals of BMO with dimensions up to 83 mm × 65 mm × 55 mm were sucessfully grown in the Bi2O3–MoO3 hybrid-flux solutions by the top-seeded solution growth (TSSG) method. Spontaneous polarized Raman spectra of BMO crystals were systematically measured and analyzed based on microvibrations of the composing Raman active ionic groups. Through comparison, it was found that BMO crystals had a large Raman gain coefficient, 1.1 times that of the mostly used YVO4 crystals. Besides, under the pump of a 1064 nm laser, a first-order Raman laser at 1176 nm, and dual-wavelength of both first-order and second-order at 1315 nm, were achieved under the Y(ZZ)Y and Y(XX)Y configurations, respectively. A maximum output power of 1.12 mW, corresponding to an optical-to-optical conversion efficiency of 15.6%, was successfully achieved. This work provides systematic analysis of the polarized Raman spectra of BMO crystals and reveals their great application prospects as novel Raman laser crystals. [ABSTRACT FROM AUTHOR]

In the present research work, we have explored amperometric sensing properties of carbon nanospheres (Cx) (5%, 8%, and 15%) decorated over Sm2O3/Co3O4 nanocomposites (NC) that are synthesized by microwave-assisted method. The synthesized electrode materials are characterized by the techniques of X-ray diffraction (XRD), scanning electron microscopy (SEM), SEM-EDAX (energy-dispersive X-ray spectroscopy), BET (Brunauer–Emmett–Teller), XPS (X-ray photoelectron spectroscopy), and UV–visible. Phase analysis revealed mixed monoclinic crystal structure and crystallite size decreases from 32 to 22 nm. Plate/flake-like morphology resulted upon the incorporation of Cx on Sm2O3/Co3O4 crystal lattice. Redshift in the optical absorption peak resulted with an increase in Cx concentration on Sm2O3/Co3O4 NC and the optical band gap (Eg) decreases from 3.26 to 2.61 eV. The sensitive and selective determination of hydrogen peroxide (H2O2) is very important because it is a product of reactions catalyzed by oxidase enzymes, a powerful effector of redox signaling, versatile biomarker, and is widely used in the food industry. H2O2 is known to cause toxicity and they form hydroxyl radicals. The accurate detection of H2O2 can indicate the presence of enzyme activity, explosives, and cell signaling pathways. Additionally, H2O2 has become a signal propagator within signal amplification methodologies used to enhance selectivity of the diagnostic assays. The developed modified sensor (C15%:Sm2O3/Co3O4) showed amperometric detection of H2O2 with 96% steady current within 3–4 s, linear range was found to be 0.2 µM to 6 µM, limit of detection (LOD) 0.04 µM, and having a sensitivity of 0.483 µA/µM (R2 = 0.996). Further, sensitivity and selectivity were detected with glucose, dopamine, ascorbic acid, and uric acid at + 0.36 V and no current response was observed. The modified electrode material possess high selectivity, less response time, high stability, reusability, and high repeatability and can find applications in the field of real-time monitoring of hazardous materials, fabrication of biosensors, H2O2 sensors, and in optoelectronics. [ABSTRACT FROM AUTHOR]

Cooling [Fe(bbtr)3](BF4)2 (bbtr=1,4‐di(1,2,3‐triazol‐1‐yl)butane) triggers very slow spin crossover below 80 K (T1/2↓=76 K). The spin crossover (SCO) is accompanied by a hysteresis loop (T1/2↑=89 K). In contrast to isostructural perchlorate analogue [Fe(bbtr)3](ClO4)2 in which spin crossover during cooling is preceded by phase transition at TPT=126 K in tetrafluoroborate phase transition does not occur to the beginning of spin crossover (80 K). Studies of mixed crystals [Fe(bbtr)3](BF4)2(1‐x)(ClO4)2x (0.5≤x≤0.9) showed that a phase transition precedes spin crossover, however, for x≅0.46 intersection of T1/2(x) and TPT(x) dependencies takes place. The application of pressure of 1 GPa shifts the spin crossover in [Fe(bbtr)3](BF4)2 to a temperature above 270 K. High‐pressure studies of neat tetrafluoroborate and perchlorate, as well as mixed crystals [Fe(bbtr)3](BF4)2(1‐x)(ClO4)2x (0.1≤x≤0.9), revealed that at 295 K P1/2 value changes linearly with x indicating similar mechanism of spin crossover under elevated pressure in all systems under investigation. Variable pressure single crystal X‐ray diffraction studies confirmed that in contrast to thermally induced spin crossover undergoing differently in tetrafluoroborate and perchlorate an application of high pressure removes this differentiation leading to a similar mechanism depending at first on start spin crossover and then P‐3→P‐1 phase transition occurs. In this report we have shown that 2D coordination polymer [Fe(bbtr)3](BF4)2 (bbtr=1,4‐di(1,2,3‐triazol‐1‐yl)butane) treated to date as spin crossover silent shows thermally induced spin crossover phenomenon. Spin crossover in tetrafluoroborate is extremely slow. Determination of the spin crossover curve required carrying measurement in the settle mode‐cooling from 85 to 70 K took about 600 h (average velocity of change of temperature ca. 0.0004 K/min). [ABSTRACT FROM AUTHOR]

Cooling [Fe(bbtr)3](BF4)2 (bbtr=1,4‐di(1,2,3‐triazol‐1‐yl)butane) triggers very slow spin crossover below 80 K (T1/2↓=76 K). The spin crossover (SCO) is accompanied by a hysteresis loop (T1/2↑=89 K). In contrast to isostructural perchlorate analogue [Fe(bbtr)3](ClO4)2 in which spin crossover during cooling is preceded by phase transition at TPT=126 K in tetrafluoroborate phase transition does not occur to the beginning of spin crossover (80 K). Studies of mixed crystals [Fe(bbtr)3](BF4)2(1‐x)(ClO4)2x (0.5≤x≤0.9) showed that a phase transition precedes spin crossover, however, for x≅0.46 intersection of T1/2(x) and TPT(x) dependencies takes place. The application of pressure of 1 GPa shifts the spin crossover in [Fe(bbtr)3](BF4)2 to a temperature above 270 K. High‐pressure studies of neat tetrafluoroborate and perchlorate, as well as mixed crystals [Fe(bbtr)3](BF4)2(1‐x)(ClO4)2x (0.1≤x≤0.9), revealed that at 295 K P1/2 value changes linearly with x indicating similar mechanism of spin crossover under elevated pressure in all systems under investigation. Variable pressure single crystal X‐ray diffraction studies confirmed that in contrast to thermally induced spin crossover undergoing differently in tetrafluoroborate and perchlorate an application of high pressure removes this differentiation leading to a similar mechanism depending at first on start spin crossover and then P‐3→P‐1 phase transition occurs. In this report we have shown that 2D coordination polymer [Fe(bbtr)3](BF4)2 (bbtr=1,4‐di(1,2,3‐triazol‐1‐yl)butane) treated to date as spin crossover silent shows thermally induced spin crossover phenomenon. Spin crossover in tetrafluoroborate is extremely slow. Determination of the spin crossover curve required carrying measurement in the settle mode‐cooling from 85 to 70 K took about 600 h (average velocity of change of temperature ca. 0.0004 K/min). [ABSTRACT FROM AUTHOR]

CdS‐based materials are extensively studied for photocatalytic water splitting. By incorporating Ag+ into CdS nanomaterials, the catalyst's charge carrier dynamic can be tuned for photo‐electrochemical devices. However, photo‐corrosion and air‐stability of the heterostructures limit the photocatalytic device's performance. Here, a one‐pot, single molecular source synthesis of the air‐stable AgCdS ternary semiconductor alloy nanostructures by heat‐up method is reported. Monoclinic and hexagonal phases of the alloy are tuned by judicious choice of dodecane thiol (DDT), octadecyl amine (ODA), and oleyl amine (OLA) as capping agents. Transmission electron microscope (TEM) and powder X‐ray diffraction characterization of the AgCdS alloy confirm the monoclinic and hexagonal phase (wurtzite) formation. The high‐resolution TEM studies confirm the formation of AgCdS@DDT alloy nanorods and their shape transformation into nano‐triangles. The nanoparticle coalescence is observed for ODA‐capped alloys in the wurtzite phase. Moreover, OLA directs mixed crystal phases and anisotropic growth of alloy. Optical processes in AgCdS@DDT nano‐triangles show mono‐exponential decay (3.97 ± 0.01 ns). The monoclinic phase of the AgCdS@DDT nanorods exhibits higher electrochemical hydrogen evolution activity in neutral media as compared to the AgCdS@ODA/OLA alloy nanocrystals. DDT and OLA‐capped alloys display current densities of 14.1 and 14.7 mA cm−2, respectively, at 0.8 V (vs RHE). [ABSTRACT FROM AUTHOR]

The influence of ion irradiation on intrinsic lattice stress and phase transition is closely related to the irradiation resistance of high‐entropy ceramics. In this study, the ion‐induced response of high‐entropy‐stabilized o‐(ZrHfTiSn)O2 ceramic was investigated under Au2+ irradiation with different fluences. The results revealed that high‐fluence irradiation caused the minimal (orthorhombic‐to‐triclinic) phase transformation underneath the ion‐induced amorphous layer via. fast fourier transformation (FFT) pattern. The cation recombination led to cation rearrangement followed by the increase of lattice expansion induced stress. The lattice stability of residual crystal grains in the mixed layer was significantly improved after lattice rearrangement. This was evidenced by the fact that the X‐ray diffraction profile of the lattice remained unchanged, whereas the selected area electron diffraction (SAED) image exhibited drastic variations with the increase of irradiation fluence. Therefore, irradiation‐induced lattice rearrangement seems to be a reliable way to improve radiation resistance of high‐entropy ceramics. [ABSTRACT FROM AUTHOR]

Considering the anisotropy of wurtzite semiconductors, the interface optical phonons in double-channel AlGaN/GaN heterostructures are investigated by using a dielectric continuous model and transfer matrix method. Also, the ternary mixed crystal effect and size effect on the dispersion relations and electrostatic potentials of phonons are analyzed in detail. The results show that there are six branches of interface phonon modes in a double-channel heterostructure. For some values of Al composition, however, the phonon mode with the highest frequency may not exist, especially when the thicknesses of materials and the wave vectors of phonons are small. The ternary mixed crystal effect and size effect not only influence the values of phonon frequency and electrostatic potential, but also change the vibration mode of interface phonons. This suggests that the interface phonon vibrations can be controlled to reduce their adverse effects by changing the Al composition of AlGaN and the thickness of each layer in a double-channel heterostructure. [ABSTRACT FROM AUTHOR]

Models assume that mixed‐phase clouds consist of uniformly mixed ice crystals and liquid cloud droplets when observations have shown that they consist of clusters, or "pockets," of ice crystals and liquid cloud droplets. We characterize the spatial distribution of cloud phase over the Arctic and the Southern Ocean using active satellite observations and determine the relative importance of collocated meteorological parameters and aerosols from reanalysis to predict how uniformly mixed mixed‐phase clouds are for the first time. We performed a multi‐linear regression fit to the data set to predict the spatial distribution of the ice and liquid pockets. Contrary to what models suggest, mixed‐phase clouds are rarely perfectly homogeneous. Our results suggest that high temperatures are associated with homogeneously mixed ice and liquid pockets. We also find that a high mixing ratio of black carbon is associated with heterogeneously mixed ice and liquid pockets. Plain Language Summary: The representation of clouds in numerical models remains one of the largest uncertainties in predicting our future climate. Clouds can consist solely of liquid droplets, ice crystals, or the coexistence of both hydrometeor types. The latter cloud type is referred to as mixed phase. Climate models assume that liquid droplets and ice crystals are uniformly mixed in space in mixed‐phase clouds, but observations show that mixed‐phase clouds are organized in separate pockets of clustered liquid droplets and ice crystals. This difference in representation has a large impact on the lifetime of clouds and on their role in climate change. Using satellite observations over the Arctic and the Southern Ocean, we quantify the spatial distribution of ice and liquid in clouds. We used a statistical method to determine the relationship between meteorology and aerosols and the spatial distribution of ice and liquid. Our results suggest that high temperatures are associated with homogeneously mixed mixed‐phase clouds and high concentrations of soot are associated with heterogeneously mixed mixed‐phase clouds. Furthermore, pockets of liquid within ice clouds are larger than pockets of ice within liquid clouds. These results will improve the representation of mixed‐phase clouds in large‐scale models. Key Points: Space‐based observations and reanalysis are considered to determine the factors that control how mixed mixed‐phase clouds areLiquid dominated clouds contain small and isolated ice pockets whereas ice dominated clouds contain large and isolated liquid pocketsTemperature and black carbon play an important role in controlling the cloud phase spatial distribution and increasing phase heterogeneity [ABSTRACT FROM AUTHOR]

The search for solid solutions of class-two insulin secretagogues, tolbutamide and chlorpropamide, reveals a rare case of monotropic polymorphism for the mixed crystals. At any stoichiometry, two crystal forms are isolated that are kinetically stable at room temperature from a few months to over a year. Dissolution tests certify the solubility advantage of the solid solutions over the pure drugs as well as their physical mixture, suggesting a potential application as a highly soluble co-drug formulation. [ABSTRACT FROM AUTHOR]

Flexible molecular crystal waveguides based on elastic molecular crystals (EMCs) are essential in flexible and compact optical materials. An increased loss coefficient α due to self‐absorption is often a problem in optical waveguides (OWGs) of fluorescent chemical materials waveguiding photons in active mode. Herein, the development of anthracene‐based elastic mixed molecular crystals (EMMCs) is reported for Förster Resonance Energy Transfer (FRET)‐assisted OWG. To yield a FRET crystal system based on elastic molecular crystals, 1%–5% acceptor doping for fluorescent molecular crystals of 9,10‐dibromoanthracene 1 was successful by selecting the same regioisomer having electron‐withdrawing group, 9,10‐diformylanthracene 2, as a dopant. In addition to conversion to the mixed system, there is a difference in the elastic modulus and hardness in EMC C1 and EMMC C2@1. However, the elastic behaviour was also shown in a few percent doping of the acceptor. The α value of this EMMC, composed of 1 including 1% of 2 (0.0077 dB/μm), is much lower than that of EMC composed of 1 (0.1258 dB/μm) because of reducing self‐absorption in the FRET system. An efficient and flexible OWG was successfully developed by selecting an appropriate acceptor molecule and its low doping rate for mixed crystal construction. This method is a practical approach in various functional and flexible crystal systems. [ABSTRACT FROM AUTHOR]

Three oleogelator molecules (Triacontane (TC), Stearic acid (SA), and Behenyl Lignocerate (BL)) were studied individually, in pairs, or all together to make an oleogel using triolein as the oil. WAXS, SAXS and USAXS were used to elucidate the solid structures from angstroms to a few micrometers. A two‐dimensional mapping of atomic positions for each molecule was carried out to understand the crystalline multilayer structures formed. We assumed that the molecules were rigidly extended and that they underwent no significant (hindered) rotations so that the free energy is determined by the Lennard‐Jones interactions of closely packed multilayers. TC molecules were predicted to form a tilt angle of θt≈33°, yielding a SAXS line at q≈0.194 Å─1, in acceptable agreement with the measured q=0.181Å−1. For SA crystals θt≈33° (predicted) yielding a SAXS line at q=0.150Å−1 compared to q=0.159Å−1 (observed). No mixed crystals were observed for any pair of molecules or when all three were used. USAXS data showed that SA forms large nanocrystals compared to TC and BL. All three combinations of molecular pairs showed basic scatterers smaller or similar to those of individual molecules. The theory presented here, together with the experimental results, showed why no mixed crystals are formed from two or all three molecules. Data from the USAXS region suggested that, when using all three molecules, a more compact fractal structure was obtained, compared with those if one or two of the molecules were used. [ABSTRACT FROM AUTHOR]

Two distinct compositions of mixed garnet crystals, codoped with Dy3+ and Tb3+ ions, were grown using the Czochralski method. The structures and thermal properties of these crystals were thoroughly examined, and the influence of the doped ions on their structure and thermal properties was analyzed. Additionally, a straightforward and reliable method was introduced for accurately determining the specific heat and thermal diffusivity of garnet crystals across a wide temperature range, extending from room temperature to elevated temperatures. The absorption properties of the crystals were investigated, and their bandgap energies were determined using the Tauc formula. The relationship between the bandgap energy of garnet crystals and the radius of cations corroborates Yadav's prediction. Furthermore, the emission characteristics of the crystals under blue, UV, and VUV excitation were thoroughly studied. A proposed mechanism for energy transfer between Dy3+ and Tb3+ ions in the mixed garnet crystals was elucidated based on the absorption and emission characterization. The results indicate that the mixed garnet crystals exhibit distinct advantages for the development of blue laser diode pumped yellow lasers. Overall, this study provides valuable insights into the structural, thermal, optical, and energy transfer properties of mixed garnet crystals, highlighting their potential applications in all solid-state yellow laser technology. [ABSTRACT FROM AUTHOR]

Glancing angle deposition (GLAD) of CdTe can produce a cubic, hexagonal, or mixed phase crystal structure depending upon the oblique deposition angles (Φ) and substrate temperature. GLAD CdTe films are prepared at different Φ at room temperature (RT) and a high temperature (HT) of 250 °C and used as interlayers between the n-type hexagonal CdS window layer and the p-type cubic CdTe absorber layer to investigate the role of interfacial tailoring at the CdS/CdTe heterojunction in photovoltaic (PV) device performance. The Φ = 80° RT GLAD CdTe interlayer and CdS both have the hexagonal structure, which reduces lattice mismatch at the CdS/CdTe interface and improves electronic quality at the heterojunction for device performance optimization. The device performance of HT CdS/CdTe solar cells with Φ = 80° RT with 50 to 350 nm thick GLAD CdTe interlayers is evaluated in which a 250 nm interlayer device shows the best device performance with a 0.53 V increase in open-circuit voltage and fill-factor product and a 0.73% increase in absolute efficiency compared to the HT baseline PV device without an interlayer. [ABSTRACT FROM AUTHOR]

To generate reliable climate predictions, global models need accurate estimates of all the energy fluxes contributing to the Earth Radiation Budget (ERB). Clouds in general, and more specifically ice clouds play a key role in the determination of the ERB, as they may exert either a feedback or a forcing action, depending on their optical and microphysical properties and physical state (solid/liquid). To date, accurate statistics and climatologies of cloud parameters are not available. The ice cloud composition in terms of ice crystal shape (or habit) is one of the parameters with the largest uncertainty. This is because crystal shape estimates are generally hard to extract from space measurements. Satellite spectral radiance measurements available to date, are actually limited to the middle-infrared spectral region, therefore their information on ice cloud crystal habits is not sufficient to attempt a retrieval. The Far-infrared Outgoing Radiation Understanding and Monitoring (FORUM) experiment, foreseen to be the 9 th Earth Explorer mission of the European Space Agency, will measure, for the first time spectrally resolved from space, the entire upwelling spectrum emitted by the Earth, from 100 to 1600 cm-1. The far-infrared portion of the Earth spectrum, especially from 200 to 600 cm-1, is very sensitive to cloud ice crystal shapes, thus FORUM measurements could also represent an opportunity to study the ice cloud composition in terms of ice crystal habit mixtures. To investigate this possibility, we developed an accurate and advanced scheme allowing to model ice cloud optical properties also in cases of clouds composed of mixed ice crystal habits. This feature is in fact necessary, because also in situ measurements acquired over the years point out that the shape of ice cloud crystals varies depending on the crystal size range. In our model, the resulting cloud optical properties are also determined by the input habit fractions. Thus, the retrieval of these fractions from spectral radiance measurements can be attempted. Using 375 different cloudy scenarios, we assess the performance of our retrieval scheme in the determination of crystal habit mixtures starting from FORUM simulated measurements. The most relevant error components affecting the retrieved cloud parameters are not very large and are of random nature, thus FORUM measurements will allow to set up an accurate climatology of cloud parameters. To provide an example of the benefit that one could get out of the habit mixture retrievals, we also show the improved accuracy of the thermal outgoing fluxes calculations as compared to using assumed mixtures. [ABSTRACT FROM AUTHOR]

The dipole ordering in Sn (Pb) 2 P 2 S (Se) 6 materials may be tuned by chemical substitution realizing a ferroelectric quantum phase transition and quantum glassy or relaxor type phenomena on different parts of the phase diagram. The introduction of Ge impurity increases the temperature of the phase transitions and initiates a more pronounced Ising type critical anomaly in the Sn 2 P 2 S 6 crystal, does not shift the coordinate of the Lifshitz point x LP in Sn 2 P 2 (Se x S 1 − x) 6 mixed crystals, and induces the appearance of a ferroelectric phase transition in quantum paraelectrics Pb 2 P 2 S 6 and inhomogeneous polar ordering in (Pb 0.7 Sn 0.3) 2 P 2 S (Se) 6 crystals. For the Pb 2 P 2 S 6 crystal, the real part of the dielectric permittivity in the quantum critical regime varies as 1 / T 2 instead of the expected 1 / T 3 behavior for uniaxial materials. Such an observation can be partially explained by a screening phenomenon in the semiconductor materials of the Sn (Pb) 2 P 2 S (Se) 6 system, which weakens the long-range electric dipole interactions, and also provides, at high temperatures, a critical behavior near the Lifshitz point (studied by thermal diffusivity) similar to the one predicted in the case of systems with short-range interactions. At low temperatures, a quantum critical behavior in the Pb 2 P 2 S 6 crystal can be established by a small amplitude of electric dipoles together with the nonlinear coupling between polar and antipolar fluctuations. An increase in thermal conductivity is induced by Ge impurity in the Pb 2 P 2 S 6 crystal, which is explained by the weakening of the acoustic phonons resonance scattering by soft optic phonons because of the appearance of ferroelectric phase polar clusters. [ABSTRACT FROM AUTHOR]

The whole optical phonon spectrum of quasiconfined (CO), propagating (PR), and interface (IF) modes in wurtzite III-nitride cylindrical core-multishell nanowires (CMSNWs) is obtained based on the dielectric continuum and Loudon's uniaxial crystal models considering the ternary mixed crystal effect. A transfer matrix method calculation shows that there are six types of CO modes and one type of PR mode in a three-layered CMSNW. For any fixed component, only permitted types of CO modes exist in allowable frequency regions, while the PR modes appear only when components are almost the same in all layers, originating from anisotropic optical phonons in bulk wurtzite nitride. The whole spectrum reveals two mode transformations: one is between PR and IF modes by adjusting components in different layers; the other is continuous among five possible modes at any fixed component with connected frequency regions. The dispersion relations and corresponding electrostatic potentials of the whole optical phonon spectrum are helpful to understand the frequency-dependent electron–phonon interaction in the future. The analysis process can be extended to arbitrary nitride cylindrical CMSNWs for the modulation of optical phonon related properties. [ABSTRACT FROM AUTHOR]

Black needle‐shaped crystals of the bismuth‐rich mixed halogenide Bi21Rh4Cl6I7 were obtained by slow cooling of a melt of Bi, RhI3 and BiCl3. Single‐crystal X‐ray diffraction revealed an orthorhombic structure that consists of infinite intermetallic rods ∞1[ ${{}_{\infty }{}^{1}[}$ Bi9Rh2]3+ and discrete anionic groups [BiII2Cl2I5]3− and [BiIIICl4I2]3−. The rods consist of Rh‐centered [RhBi8] polyhedra that alternately share triangular and rectangular faces. Using traditional electron counting rules, the rod can be interpreted as a covalent polymer with Rh2 dumbbells bonded to molecular Bi2 and Bi5 units. However, a quantum‐chemical bonding analysis shows that the bonds involving Rh atoms are largely diffuse, while two‐center bonds dominate in the bismuth units. The below 240 K observed semiconducting behavior of Bi21Rh4Cl6I7 is consistent with a complete localization of the valence electrons. Above 240 K, the resistance along the needle axis is largely independent of temperature. [ABSTRACT FROM AUTHOR]