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Metal lead perovskite (MHP) single crystals (SCs) with extraordinary optical properties are promising candidates for high‐performance SC‐based perovskite light‐emitting diodes (SC‐PeLEDs). However, the heating process involved in traditional methods to initiate crystal nucleation and growth inevitably induces massive defects in MHP SCs, leading to inferior electroluminescence performance and poor operational stability of the SC‐PeLEDs. Preparation of low‐defect thin MHP SCs for high‐performance SC‐PeLEDs remains a formidable challenge. Here, a facile pre‐nucleation strategy is developed to enable room‐temperature (RT) growth of high‐quality MAPbBr3 (MA+ = CH3NH3+) SCs. By avoiding the detrimental effect of high growth temperature, the MAPbBr3 SCs prepared at RT show improved crystallinity with lower trap‐state density, giving rise to higher photoluminescence quantum yield and uniform fluorescence. Consequently, the MAPbBr3‐based SC‐PeLEDs achieve a high external quantum efficiency up to 9.7%, along with an ultrahigh luminance of 126 800 cd m−2, which is among the highest for MAPbBr3‐based SC‐PeLEDs. Moreover, the SC‐PeLEDs demonstrate remarkably high operational stability with half‐lifetimes as long as 594 min and 33.2 min at initial luminances of ≈1000 cd m−2 and ≈10 000 cd m−2, respectively. The work has excellent universality and paves the way toward the fabrication of high‐performance SC‐PeLEDs for future lighting, display, and laser applications. [ABSTRACT FROM AUTHOR]

In 2D materials, tungsten diselenide (WSe2) has great potential for optical and electronic devices. However, the quality of WSe2 crystals, determined by defects and grain boundaries, currently restricts its performance in controlling carrier‐transport properties. Consequently, the most significant issue achieves superior growth of WSe2 crystals and appropriate metal contacts. Herein, a doping‐free approach to manipulate the polarity of WSe2 transistors by utilizing distinct metal contacts is presented. WSe2 field‐effect transistors are examined employing low‐ and high‐work function metals. In these findings, a transition in polarity from n‐type for In and Cr to p‐type for Pd and Au is demonstrated, showcasing remarkably high on/off ratios (≈107) and mobilities (≈117 cm2 V−1 s−1) at room temperature. This straightforward polarity control technique can be further extended by utilizing contact architecture‐based research in other 2D materials for future nano‐electrical and optoelectronic devices. [ABSTRACT FROM AUTHOR]

Literature on Group One organoelement chemistry is dominated by lithium, though sodium and potassium also feature prominently, whereas rubidium and caesium are rarely mentioned. With recent breakthroughs hinting that organoelement compounds of these two heavier metals can perform better than their lighter congeners in particular applications, important advantages could be missed unless complete sets of alkali metals are included in studies. Here, we report the synthesis and characterisation of a complete set of multi‐alkali‐metallated molecular compounds of the 1,3,5‐tris[(4,6‐dimethylpyridin‐2‐yl)aminomethyl]‐2,4,6‐triethylbenzene framework. Made by deprotonating the framework N−H bonds by a suitable base, the set comprises six THF‐solvated compounds, four of which are homometallic, either containing Li in a trinuclear structure or Na, K, and Rb in hexanuclear structures. Since deprotonation was incomplete with Cs, its homometallic compound is tetranuclear containing two un‐metallated N−H bonds. A heterobimetallic trilithium‐tricaesium hexanuclear compound was also obtained by using a bimetallic Li−Cs base for deprotonation. Such alkali‐metallated frameworks are often precursors to other multimetallic frameworks with unique properties across different fields of science. [ABSTRACT FROM AUTHOR]

We have developed a circularly polarized dielectric rutile (TiO2) cavity with a high quality-factor that can generate circularly polarized microwaves from two orthogonal linearly polarized microwaves with a phase difference of ±π/2 using a hybrid coupler. Using this cavity, we have established a new methodology to measure the microwave Hall conductivity of a small single crystal of metal in the skin-depth region. Based on the cavity perturbation technique, we have shown that all components of the surface impedance tensor can be extracted under the application of a magnetic field by comparing the right- and left-handed circularly polarized modes. To verify the validity of the developed method, we performed test measurements on tiny Bi single crystals at low temperatures. As a result, we have successfully obtained the surface impedance tensor components and confirmed that the characteristic field dependence of the ac Hall angle in the microwave region is consistent with the expectation from the dc transport measurements. These results demonstrate a significant improvement in sensitivity compared to previous methods. Thus, our developed technique allows for more accurate microwave Hall measurements, opening the way for new approaches to explore novel topological quantum phenomena, such as time-reversal symmetry breaking in superconductors. [ABSTRACT FROM AUTHOR]

We describe a compact calorimeter that opens ultra-low-temperature heat capacity studies of small metal crystals in moderate magnetic fields. The performance is demonstrated on the canonical heavy fermion metal YbRh 2 Si 2 . Thermometry is provided by a fast current sensing noise thermometer. This single thermometer enables us to cover a wide temperature range of interest from 175 µK to 90 mK with temperature-independent relative precision. Temperatures are tied to the international temperature scale with a single-point calibration. A superconducting solenoid surrounding the cell provides the sample field for tuning its properties and operates a superconducting heat switch. Both adiabatic and relaxation calorimetry techniques, as well as magnetic field sweeps, are employed. The design of the calorimeter results in an addendum heat capacity which is negligible for the study reported. The keys to sample and thermometer thermalisation are the lack of dissipation in the temperature measurement and the steps taken to reduce the parasitic heat leak into the cell to the tens of fW level. [ABSTRACT FROM AUTHOR]

In this paper, we introduce a comprehensive theoretical study to obtain an optimal highly sensitive fluidic sensor based on the one-dimensional phononic crystal (PnC). The mainstay of this study strongly depends on the high impedance mismatching due to the irregularity of the considered quasi-periodic structure, which in turn can provide better performance compared to the periodic PnC designs. In this regard, we performed the detection and monitoring of the different concentrations of lead nitrate (Pb(NO3)2) and identified it as being a dangerous aqueous solution. Here, a defect layer was introduced through the designed structure to be filled with the Pb(NO3)2 solution. Therefore, a resonant mode was formed within the transmittance spectrum of the considered structure, which in turn shifted due to the changes in the concentration of the detected analyte. The numerical findings demonstrate the role of the different sequences such as Fibonacci, Octonacci, Thue–Morse, and double period on the performance of the designed PhC detector. Meanwhile, the findings of this study show that the double-period quasi-periodic sequence provides the best performance with a sensitivity of 502.6 Hz/ppm, a damping rate of 5.9 × 10 − 5 , a maximum quality factor of 8463.5, and a detection limit of 2.45. [ABSTRACT FROM AUTHOR]

Compared to many conventional manufacturing methods, Additive Manufacturing/3D Printing (AM/3DP) techniques can produce highly optimized builds with unparalleled structural complexities, material combinations, and both internal and external geometrical intricacies, offering new degrees of freedom for optimization. However, unforeseen deviations in process parameters (e.g., laser beam scan speeds and power), material properties (e.g., powder morphology, alloy composition, mechanical and thermal properties), and machine health can lead to micro/macro-scale defects and quality concerns in the resulting builds and end-products. To address these concerns, it is crucial to assess quality and implement effective closed-loop control by understanding the sensitivity of quality attributes to perturbations and variations in process parameters, material properties, and machine health state. AM print speeds influence the material's microstructure, affecting its elastic properties, defect states, and, consequently, spectral resonance behavior. Here, a quality monitoring framework is introduced based on specially designed Phononic Crystal Artifacts (PCAs) printed alongside the actual build. Compared to the actual build, a PCA is a substantially smaller construct with a repeating pattern (periodic) internal structure to effectively capture and measure the build's defect state and mechanical and geometric complexities for quality assessment. In this study, we investigate the impact of varying print speeds in AM on the resonance frequencies of PCAs, which are related to mechanical properties and defects. Stainless steel 316L powder, widely used in powder-based AM/3DP, was chosen to print the Metal Phononic Crystal Artifacts (mPCAs). Our findings indicate that varying print speeds significantly influence ultrasonic waves' resonance and modal frequencies in the printed artifacts. Specifically, high print speeds resulted in measurable shifts in these frequencies, demonstrating the potential for real-time quality monitoring and process optimization in AM/3DP. The PCA approach offers real-time, non-destructive quality monitoring by using smaller, sensitive constructs to capture essential mechanical and geometric complexities, allowing for dynamic adjustment of print speeds and enhancing overall build precision and reliability in AM/3DP. [ABSTRACT FROM AUTHOR]

Chiral organic–inorganic hybrid lead halides have recently attracted great attention due to their unique chirality and diverse functional properties. However, they suffer from highly toxic lead, while lead‐free chiral hybrid metal halides especially those with phase transitions remain sparse. Here, we report a new lead‐free chiral metal halide crystal [R‐3‐fluoropiperidinium]2SbCl5 ([R‐3‐FPP]2SbCl5), which crystalizes in chiral P212121 space group at 293 K and consists of chiral [3‐FPP]+ cations and one‐dimensional [SbCl5]n2− zigzag chains of corner‐sharing SbCl6 octahedrons. Notably, [R‐3‐FPP]2SbCl5 undergoes an above room temperature phase transition at 313 K, which can be attributed to the order‐disorder transition of both the organic [R‐3‐FPP]+ cation and inorganic [SbCl5]2− anions. In addition, [R‐3‐FPP]2SbCl5 also shows a broad band gap of 3.21 eV. This work promotes the exploration of chiral lead‐free hybrid lead halides with phase transitions. [ABSTRACT FROM AUTHOR]

π–π stacking interactions are versatile because they are involved in many processes, such as protein folding, DNA stacking, and drug recognition. However, from the point of view of crystal engineering, there is an incipient knowledge of its exploitation. A comparison of these interactions with hydrogen bonds shows a huge difference in their employment as a reliable non-covalent interaction. And different reasons can be listed to explain why hydrogen bonding can be considered a more robust interaction than π−π stacking. For instance, hydrogen bonds encompass a wide energy range (25–40 kJ mol−1). From this, these interactions can be classified as strong, moderate, and weak. Hence, the first two can be considered highly to moderately directional to be exploited in crystal engineering. This aspect is relevant for them to be used in a relatively reliably way in this area of supramolecular chemistry. On the other hand, in the case of π−π stacking, the energy range is 0–10 kJ mol−1, thus implying that hydrogen bonds or any other energetically more robust contact would predominate in the competition for establishing packing interactions in a given arrangement. In this sense, if stacking is pretended to be exploited from the point of view of crystal engineering, one of the points that must be ensured is that this interaction will be the one energetically predominant. However, although there are other factors to consider, it seems that energetics is the dominant one. In this line, our research group has obtained and studied many single-crystalline structures of coordination and organometallic compounds containing fluorinated thiolates. This being particularly true in the case of the thiolate 2,3,5,6-S(C6F4H-4) bound to different metals, where it has been observed that they preferentially tend to establish πF–πF stacking interactions, results that have been reported in several papers. Thus, from this perspective, we have explored, using ConQuest (CCDC) a number of structures to observe how feasible is to find stacking in coordination and organometallic compounds containing the thiolate 2,3,5,6-S(C6F4H-4). [ABSTRACT FROM AUTHOR]

The deposition of diamond films on tungsten carbide-based tools can greatly improve the life and performance of cutting tools. However, the deposition of diamond coatings on cemented carbide (WC-Co) suffers from poor film-base bond strength. In this paper, diamond coatings were deposited of phytocrystalline metal micropowders (pure, Nb, Ti, Ta) pretreatment method and the properties of diamond films were analyzed by energy spectrometry (EDS), scanning electron microscopy (SEM), Raman spectroscopy and bonding strength test of diamond films. The results show that through the experiment of the pretreatment process of surface implanted crystal metal micropowder, the best implanted crystal metal micropowder was obtained, the surface quality of implanted crystal titanium (Ti) coating was improved, the diamond Raman peaks were sharp and the indentation cracks had a crack diameter of 389 μm, which is small and has the highest bond strength. The pretreatment process of phytocrystalline diamond micropowder can deposit high-performance diamond coatings and improve the bonding strength between the coating and the substrate film base. [ABSTRACT FROM AUTHOR]

By engineering chemically identical but structurally distinct materials into intricate and sophisticated polytypic nanostructures, which often surpass their pure phase objects and even produce novel physical and chemical properties, exciting applications in the fields of photovoltaics, electronics and photocatalysis can be achieved. In recent decades, various methods have been developed for synthesizing a library of polytypic nanocrystals encompassing IV, III–V and II–VI polytypic semiconductors. The exceptional performances of polytypic metal chalcogenide nanocrystals have been observed, making them highly promising candidates for applications in photonics and electronics. However, achieving high-precision control over the morphology, composition, crystal structure, size, homojunctions, and periodicity of polytypic metal chalcogenide nanostructures remains a significant synthetic challenge. This review article offers a comprehensive overview of recent progress in the synthesis and control of polytypic metal chalcogenide nanocrystals using colloidal synthetic strategies. Starting from a concise introduction on the crystal structures of metal chalcogenides, the subsequent discussion delves into the colloidal synthesis of polytypic metal chalcogenide nanocrystals, followed by an in-depth exploration of the key factors governing polytypic structure construction. Subsequently, we provide comprehensive insights into the physical properties of polytypic metal chalcogenide nanocrystals, which exhibit strong correlations with their applications. Thereafter, we emphasize the significance of polytypic nanostructures in various applications, such as photovoltaics, photocatalysis, transistors, thermoelectrics, stress sensors, and the electrocatalytic hydrogen evolution. Finally, we present a summary of the recent advancements in this research field and provide insightful perspectives on the forthcoming challenges, opportunities, and future research directions. [ABSTRACT FROM AUTHOR]

The transformation of energetic materials into metal salts can enhance their thermal stability. A series of high-energy metal salts comprising sodium ions (4), potassium ions (5), rubidium ions (6), and cesium ions (7) were synthesized based on 3-(dinitromethanidyl)-[1,2,4]triazolo[5,1-c][1,2,4](triazin-4-yl)(nitro)amide (DTT). The elemental composition and crystal structures of compound 5–7 were determined using techniques such as nuclear magnetic resonance spectroscopy, infrared spectroscopy, and X-ray diffraction analysis. Crystallographic studies showed that the metal salt crystals had structural stability, likely due to the incorporation of metal ions into the compound. The compounds 5–7 underwent rigorous testing using differential scanning calorimetry (DSC) and thermo gravimetric analysis (TGA), which validated their thermal stability. The incorporation of metal ions induced notable modifications to the crystal packing and overall structure, endowing the high-energy salts with advantageous properties such as density (1.907–2.477 g cm−3), resistance to elevated temperatures (Td ≥ 270.39 °C) and good detonating properties. (D ≥ 7353 m s−1, P ≥ 21.3 GPa). [ABSTRACT FROM AUTHOR]

Surface, interface, and subsurface in catalysts are broadly perceived as independent units in materials, relying on diverse bonding environments and are recurrently studied discretely because of experimental challenges in distinguishing the surface and subsurface effects. Metal crystals, isolated atoms, or metal nanoparticles in supported catalysts induce an electrophilic nature in subsurface, enhancing the catalysis efficiency. In this review, the influence of modification in subsurface of catalysts and their specific catalytic outputs are discussed. Key approaches and techniques for insertion of subsurface modifications and impact of electrophilicity upon catalysis upgradation are observed. A compilation of frequently used chemical reactions catalyzed by subsurface‐modified catalysts have been structured and thoroughly illustrated. [ABSTRACT FROM AUTHOR]

The progress of modern electronics largely depends on the discovery and use of new materials with unique properties. One of such promising materials is carbon nanotubes. Their outstanding mechanical, thermal, and electrical properties open up new possibilities for creating small-sized electronic devices and improving the characteristics of existing materials by improving their manufacturing and processing technologies. One of the unique features of carbon nanotubes is their ability to encapsulate other atoms or molecules within their structure. This property can be used to create nanocontainers capable of protecting and transporting active substances or to change the electronic properties of nanotubes depending on the encapsulated substance. In this work, crystals of alkali metal iodides MI were encapsulated in carbon nanotubes with different structures and characteristics. The results obtained in terms of energy and density spectra of the state indicate the characteristics of conductivity due to an increase in energy and high peaks in the Fermi level. Thus, carbon nanotubes represent an important material for future developments in the field of nanoelectronics and nanotechnology. [ABSTRACT FROM AUTHOR]

Magneto-electric effect, i.e. an appearance of magnetisation induced by electric current, is allowed by symmetry in metals with crystal structure without space inversion. The microscopic origin of this effect is spin–orbit coupling of electrons with a non-centrosymmetric crystal lattice lifting spin degeneracy of electron energy and mixing spin and orbital degrees of freedom. The presented here calculation of magnetisation induced by current is based on the application of kinetic equation for the matrix distribution function of electrons occupying the states in two bands split by the spin–orbit interaction. [ABSTRACT FROM AUTHOR]

The impact of elastic energy anisotropy on the drag thermopower in noble metals at low temperatures has been investigated. In order to describe the interaction of electrons with longitudinal phonons, the strain potential theory has been employed. In calculating electron relaxation on shear components of vibrational modes, the electron–phonon interaction constant, previously determined from a comparison of the calculated electrical resistivity of Au, Ag, and Cu bulk crystals with experimental data, was used. The maximum values of the drag thermopower in perfect noble metal crystals have been determined. These values are independent of the electron–phonon interaction constants; rather, they are determined by the elastic moduli of the second order, crystal density, and electron concentration. It has been demonstrated that quasi-transverse phonons constitute predominant contribution to the drag thermopower at low temperatures, whereas the contribution of longitudinal phonons were found to be negligible. At the same time, for perfect Au, Ag, and Cu crystals, the dominant contribution to the electron–phonon drag is provided by the slow t2-mode. [ABSTRACT FROM AUTHOR]

Single crystals of refractory metals with a given orientation are demanded in both the power-optics and high-power laser applications. The evolution of liquid-phase methods for growing such refractory metals as the molybdenum and tungsten single crystals is analysed. As shown, the methods for growing crystals with a single heating source cannot solve the problem of fabrication of industrial-sizes' crystals. The superlarge single crystals of various configurations, such as ingot and plates, can be grown using the combined plasmainduction method. The single-crystalline quality of the ingots and the preservation of the orientations of the selected crystallographic axes are confirmed by the x-ray method according to Laue images. The repeatability of physical and mechanical properties is shown by the indentation test. [ABSTRACT FROM AUTHOR]

Although metal nanomaterials with unconventional phases have attracted extensive attention, the lack of information on the characteristics of metal polytypes hinders the development of related research. In this work, the energetics of nonequivalent polytypes for bulk face‐centered cubic (Li, Al, Ca, Cu, Sr, Rh, Pd, Ag, Ir, Pt, Au, and Pb) and hexagonal close‐packed metals (Be, Na, Mg, Sc, Ti, Zn, Cd, Y, Zr, Tc, Ru, Hf, Re, Os, and Tl) is systematically reported. For each metal, the structural properties and energies for its polytypes with up to the periodic stacking length of L = 10 is obtained by DFT calculation. The variation tendency of the energy differences between 3C and 2H polytypes is summarized in the Periodic Table of Elements. Generally, the ratio c/(La) increases when metal crystals except Ir, Rh, Zn, and Cd leave away from their ground‐state structure. It is found that the energy difference between polytypes originates from various interactions between the two types of atomic layers: the k layer and the h layer. The work is helpful to understand not only the structural transitions in bulk metals, such as Li, Na, Sr, Ti, Al, Pb, Y, Re, and Tl, but also the evolutions of Au nanomaterials. [ABSTRACT FROM AUTHOR]

Magnesium metal batteries (MMBs), recognized as promising contenders for post‐lithium battery technologies, face challenges such as uneven magnesium (Mg) plating and stripping behaviors, leading to uncontrollable dendrite growth and irreversible structural damage. Herein, we have developed a Mg foil featuring prominently exposed (002) facets and an architecture of nanosheet arrays (termed (002)‐Mg), created through a one‐step acid etching method. Specifically, the prominent exposure of Mg (002) facets, known for their inherently low surface and adsorption energies with Mg atoms, not only facilitates smooth nucleation and dense deposition but also significantly mitigates side reactions on the Mg anode. Moreover, the nanosheet arrays on the surface evenly distribute the electric field and Mg ion flux, enhancing Mg ion transfer kinetics. As a result, the fabricated (002)‐Mg electrodes exhibit unprecedented long‐cycle performance, lasting over 6000 h (>8 months) at a current density of 3 mA cm−2 for a capacity of 3 mAh cm−2. Furthermore, the corresponding pouch cells equipped with various electrolytes and cathodes demonstrate remarkable capacity and cycling stability, highlighting the superior electrochemical compatibility of the (002)‐Mg electrode. This study provides new insights into the advancement of durable MMBs by modifying the crystal structure and morphology of Mg. [ABSTRACT FROM AUTHOR]

A complex of [Zn(pza)2(Cl)2], pza = pyrazinamide, was successfully crystallized from methanol or ethanol solvents with different morphology. The complex was synthesized using the solution method in ZnCl2: pza mol ratios of 1:2 and 1:4 in both ethanol and methanol solvents. FTIR and single crystal XRD analyses were done to confirm the complex. The complex was then used for in vitro antibacterial test against E. coli and S. aureus. Experimental data shows that the type of solvent and metal-to-ligand mol ratio yields the same compound, resulting in colorless crystals that melt at 234-236°C. Large block crystals were obtained from the methanolic solution, while a higher yield was obtained from the use of a higher mol ratio of 1:4. Infrared spectra analysis confirms the presence of characteristic carbonyl and amide groups of the pza ligand. Meanwhile, single crystal XRD screening indicates that unit cell parameters of the crystals from both solvents are identical to a known zinc(II)-pza complex. In vitro antibacterial tests against E. coli and S. aureus show that the complex had much better activity than the ZnCl2 and the free pza. In addition, the complex performs better antibacterial activity toward gram-positive S. aureus than the gram-negative E. coli. [ABSTRACT FROM AUTHOR]

As a member of 2D family, amorphous 2D nanosheets have received increasing attention due to their unique properties that are distinct from crystalline 2D nanosheets. However, compared with the vast library of crystalline 2D nanosheets, amorphous 2D nanosheets are still infancy due to the lack of an efficient synthetic approach. Here, we present a strategy that yields a library of 10 distinct amorphous 2D metal oxides/oxyhydroxides using solid-state surfactant crystals. A key feature of this process is a stepwise reaction using solid surfactant; the solid-state surfactant crystals have metal ions arranged in the interlayer space, and hydrolysis of the metal ions leads to the formation of isolated clusters in the surfactant crystals via limited condensation reactions. Immersing the surfactant crystals in formamide promotes nanosheet formation through the self-assembly of clusters by templating the morphologies of the crystals generated from surfactants crystals. Our approach opens a flatland in amorphous 2D world. The authors developed a method for creating amorphous 2D nanosheets using solid-state surfactant crystals. This strategy results in a library of 10 distinct amorphous 2D metal oxides/oxyhydroxides through stepwise hydrolysis and assembly processes. [ABSTRACT FROM AUTHOR]

Zirconium alloy with the composition of 90.1% Zr and alloying elements such as Mg, Al, and Si was investigated for its mechanical properties and corrosion resistance. The specimen was dissolved in a mixture of NaOH, Na2CO3, S, and SnO2 at 800°C for 10 min, followed by an HCl solution at room temperature for 100 cycles. The structural properties were characterized by X-ray diffraction and scanning electron microscopy, while the mechanical properties, such as tensile strength were investigated by a universal tensile machine. The microstructural observations indicated that the outside part of the crucible underwent pitting corrosion which resulted in corrosion in all directions inside that part of the crucible. The corrosion structure consisted of cracks that reached the base metal. The residual chemical from the fusion and dissolution process remained in the crack and formed NaCl, which accelerated the crack. The release rate of the zirconia oxide layer was calculated to be 8 μm per cycle. During the corrosion process at high temperatures, oxygen diffusion infiltrated the base metal and stretched the crystal lattice, causing strain hardening with the values of yield strength and ultimate tensile strength increased to 22.5% while the strain decreased by 50%. [ABSTRACT FROM AUTHOR]

Refractory metal single crystals have been applied in key high-temperature structural components of advanced nuclear reactor power systems, due to their excellent high-temperature properties and outstanding compatibility with nuclear fuels. Although electron beam floating zone melting and plasma arc melting techniques can prepare large-size oriented refractory metals and their alloy single crystals, both have difficulty producing perfect defect-free single crystals because of the high-temperature gradient. The mechanical properties of refractory metal single crystals under different loads all exhibit strong temperature and crystal orientation dependence. Slip and twinning are the two basic deformation mechanisms of refractory metal single crystals, in which low temperatures or high strain rates are more likely to induce twinning. Recrystallization is always induced by the combined action of deformation and annealing, exhibiting a strong crystal orientation dependence. The irradiation hardening and neutron embrittlement appear after exposure to irradiation damage and degrade the material properties, attributed to vacancies, dislocation loops, precipitates, and other irradiation defects, hindering dislocation motion. This paper reviews the research progress of refractory metal single crystals from three aspects, preparation technology, deformation behavior, and irradiation damage, and highlights key directions for future research. Finally, future research directions are prospected to provide a reference for the design and development of refractory metal single crystals for nuclear applications. [ABSTRACT FROM AUTHOR]

Metal oxides possessing a large surface area, pore volume and desirable pore size provide more varieties and active industrial potentials. Nevertheless, it is very challenging to produce crystal metal oxides while keeping satisfactory porosity features, especially for ternary compositions. High temperature is usually needed to produce crystal metal oxides, which readily leads to the collapse of the pore structure. Herein, by employing a 'soft' dispersant agent and a hard silica template, ZrO2, TiO2 and Zr-Ti solid solutions having a tetragonal crystal structure are produced and the silica-leached materials are characterized from macroscopic to atomistic scales. The micron-sized particulate powders are composed of nanoscale 'building blocks', with crystallite sizes between ~8 and 21 nm. These polycrystalline ceramic powders exhibit a high specific surface area (up to ~200 m2·g−1) and pore volume (up to 0.5 cm3·g−1), with a pore size range of ~5–20 nm. Importantly, the Zr/Ti–O–Si–OH chemical bonds exist on the particle surface, with about two-thirds of the surface covered by silica. The hydroxyl groups can further post-graft organic ligands or directly associate with species. Synthesized mesoporous metal oxides are highly homogenous and could potentially be used in various applications because of their tetragonal structure and porosity features. [ABSTRACT FROM AUTHOR]

Pulsed laser heating of an ensemble of Pd nanoparticles, supported by a MgO substrate, is studied by x-ray diffraction. By time-resolved Bragg peak shift measurements due to thermal lattice expansion, the transient temperature of the Pd nanoparticles is determined, which quickly rises by at least 100 K upon laser excitation and then decays within 90 ns. The diffraction experiments were carried out using a Cu x-ray tube, giving continuous radiation, and the hybrid pixel detector Timepix3 operating with single photon counting in a time-of-arrival mode. This type of detection scheme does not require time-consuming scanning of the pump-probe delay. The experimental time resolution is estimated at 15 ± 5 ns, which is very close to the detector's limit and matches with the 7 ns laser pulse duration. Compared to bulk metal single crystals, it is discussed that the maximum temperature reached by the Pd nanoparticles is higher and their cooling rate is lower. These effects are explained by the oxide support having a lower heat conductivity. [ABSTRACT FROM AUTHOR]

Establishing relationships between the distribution of atoms in a crystalline unit cell and the properties of phases is an important issue directly related to the application of functional materials. In this work, we present an analysis of the crystalline structure, chemical bonds, and prediction of material properties using the example of tetragonal phases La4-4xR4xGe3S12 (R - Er, Ho, Y, Dy, Tb), which crystallize in space group R3c. The presence of rare earth elements with high coordination in the first coordination sphere is a significant contribution to changing properties, particularly thermoelectric properties. This creates the possibility of increasing the entropy factor and, as a result, improving the thermoelectric characteristics. The parameters of the elementary cell of the initial ternary phase La4Ge3S12 decrease at a ratio of 1La:1R (R - Tb, Dy, Ho, Er) in the site 6a and 18b. In the Er-containing phase, the lowest distortion index for the [M1 8S] polyhedron, while in the [M1 9S] polyhedron it significantly increases. Additionally, the formation of "columns" from polyhedra [Ge2 6S] creates the possibility of directional excitation in one direction, which can also have a significant impact on material properties. Overall, the obtained non-symmetric materials may be promising for nonlinear optics. [ABSTRACT FROM AUTHOR]

The accumulation of heavy metal ions in the human body sharply affects health, drawing global attention. Consequently, there is an urgent need to develop environmentally-friendly and non-toxic metal ion fluorescent sensing probes. Herein, two fluorescent probes based on Cs–Bi–Cl perovskite quantum dots (PeQDs) with distinct structures, namely Cs 3 BiCl 6 :Eu3+ (3-1-6-E) and Cs 3 Bi 2 Cl 9 :Eu3+ (3-2-9-E), were successfully synthesized by using the ligand-assisted re-precipitation (LARP) method for detecting Cu2+ and Fe3+ ions in ethanol. Both PeQDs exhibit polychromatic emission, including feature emission around 505 nm and distinctive emission from Eu3+ ions in the long-wavelength region, making them suitable for ratiometric fluorescent probes. Significantly, both probes displayed excellent linear relationship with correlation coefficients of 0.998 (3-1-6-E) and 0.985 (3-2-9-E), respectively. The limit of detection (LOD) reached 6.23 μM (3-1-6-E) and 4.55 μM (3-2-9-E). Notably, the 3-2-9-E quantum dots (QDs) successfully detected Fe3+ ions in ethanol, owing to their unique photo-quenching and photo-recovery phenomena. The detection results exhibited excellent linear fitting, with a correlation coefficient of 0.996 and a low LOD of 3.6 μM. Furthermore, compared to undoped PeQDs, Eu3+ ion-doped PeQDs demonstrate strongly enhanced luminescence intensity and excellent photo-stability. This work expands the potential applications of lead-free PeQDs while simultaneously improving their luminescent properties. [ABSTRACT FROM AUTHOR]

As a class of emerging photoluminescent materials, hybrid halide crystals have drawn research attention for their potential application in the fields of light‐emitting, security, and waveguide. Nevertheless, hybrid halide crystals containing antimony with long‐term stability and tunable light emission are still increasingly in demand. In this work, serial new hybrid halide crystals (BZA)2ZnCl4·2H2O:xSb3+ (x = 0–0.2, x represents the reaction ratio) and (BZA)2SbCl5 are synthesized (BZA = 2,4‐diamino‐6‐phenyl‐1,3,5‐triazine). In (BZA)2ZnCl4·2H2O:xSb3+ crystals, Sb3+ cations replace partial Zn2+ cations to form [SbCl4]− tetrahedron. Red light emission caused by the substitution of Sb3+ for Zn2+ enhances as the doping rate increases, resulting in the tunable emission from light blue to pink and finally to dark red. There are two kinds of Sb3+ in (BZA)2SbCl5 crystal. Sb(1) has a sixfold coordination with Cl to form a [Sb(1)Cl5]∞ 1D zigzag chain. Sb(2) atom adopts a fivefold coordination with Cl and is separated from each other by BZA+ cations. (BZA)2SbCl5 crystal shows bright orange‐yellow light emission with a photoluminescence quantum yield of 45%. Moreover, the organic–inorganic hybrid metal halide crystals containing antimony have excellent long‐term stability, with phase and luminescence keeping nearly unchanged after more than six months in ambient air. [ABSTRACT FROM AUTHOR]

Spontaneous polarization plays a crucial role in manifesting unprecedented properties in polar materials, yet its mechanism remains relatively unexplored. We lack certainty regarding how asymmetric groups distort to generate spontaneous polarization, and the understanding of how spontaneous polarization changes with temperature is incomplete. In this study, we have grown a high-quality crystal of metal borate halides, specifically Mn3B7O13Cl, as a proof of principle for spontaneous polarization in polar materials. Our results for Mn3B7O13Cl indicate that approximately 80% of spontaneous polarization originates from [MnCl2O4], and the magnitude of spontaneous polarization associated with [MnCl2O4] remains nearly constant with temperature. Meanwhile, the temperature-dependent variation in spontaneous polarization is entirely governed by the [BO4–BO3] groups. These findings provide insight into the mechanism of spontaneous polarization in polar materials, particularly metal borate halides, and offer a new pathway for inducing properties related to spontaneous polarization in this class of materials. [ABSTRACT FROM AUTHOR]

Two-dimensional single crystal metals, in which the behavior of highly confined optical modes is intertwined with quantum phenomena, are highly sought after for next-generation technologies. Here, we report large area (>104 μm2), single crystal two-dimensional gold flakes (2DGFs) with thicknesses down to a single nanometer level, employing an atomic-level precision chemical etching approach. The decrease of the thickness down to such scales leads to the quantization of the electronic states, endowing 2DGFs with quantum-confinement-augmented optical nonlinearity, particularly leading to more than two orders of magnitude enhancement in harmonic generation compared with their thick polycrystalline counterparts. The nanometer-scale thickness and single crystal quality makes 2DGFs a promising platform for realizing plasmonic nanostructures with nanoscale optical confinement. This is demonstrated by patterning 2DGFs into nanoribbon arrays, exhibiting strongly confined near infrared plasmonic resonances with high quality factors. The developed 2DGFs provide an emerging platform for nanophotonic research and open up opportunities for applications in ultrathin plasmonic, optoelectronic and quantum devices. 2D metallic single crystals are sought after for nanophotonic applications, but their synthesis remains challenging. Here, the authors report an atomic level precision etching method to fabricate large-area crystalline gold flakes with nanometre thickness, showing enhanced plasmonic and nonlinear optical properties. [ABSTRACT FROM AUTHOR]

Catalytic direct deoxygenation (DDO) of phenolic compounds to aromatics is an appealing approach for utilization of biomass‐lignin with minimal amount of H2 consumption. Metal/reducible metal oxide catalysts provide two functionalities, i. e., C−H bond formation (hydrogenation) and C−O bond breakage (deoxygenation), required for this reaction that takes place at the interfacial perimeter sites. Strong metal‐support interactions (SMSI) can profoundly alter the density and property of such sites. This short review summarized recent advances in tuning SMSI for enhancing DDO of phenolics. The approaches of varying reduction temperature, modulation of crystal facets and crystal phases of metal oxide, and reduction of mixed metal oxide were discussed for the origin for formation of SMSI, the degree of SMSI, and its consequence on the DDO performance. The analysis revealed that intermediate degree of SMSI with maximal density of metal/oxide interfacial perimeter site enhances DDO while minimizing unfavorable side reactions. This short review highlights the concept of tuning the interfacial perimeter sites via SMSI for reactions which require multiple functionalities and take place at the metal/oxide interface. [ABSTRACT FROM AUTHOR]

The doping of divalent metal ions in organic crystals is used to enhance the optical properties in the present work. Pure and divalent metal ions doped anthracene single crystals are harvested using the slow evaporation solution technique in the organic solvent. The shift (≈ 0.1o) in high-intensity X-ray diffraction peak (100) reveals the structure change in doped anthracene crystals, and the Rietveld refinement of lattice parameters also confirms it. Metal ions doped anthracene crystals have enhanced the thermal stability. A blue shift in various peaks in the range of 300–450 nm of UV–Visible spectra and a broad peak in the range of 525–670 nm are observed in doped anthracene single crystals. An increment of 0.03 eV in optical energy bandgap is obtained in anthracene crystal by metal ions doping. A blue shift in all photoluminescence peaks of metal doped anthracene crystals has been seen. FESEM instrument was used to explore the growth surface and found that metal doped anthracene crystal has a smooth surface from captured images of microstructures. [ABSTRACT FROM AUTHOR]

Twist bilayer graphene (tBLG) with a small magic angle deviated from trivial stacking exhibits fantastic electronic properties. However, the growth of large‐area tBLG with precisely controlled twist angle remains a grand challenge due to the thermodynamically unfavorable nucleation. Here, a bi‐oriented step‐guided strategy is theoretically proposed for the nucleation and epitaxial growth of tBLG, where the twist angle can be predetermined by the orientations of adjacent steps owing to the covalent alignment between the steps and graphene zigzag edges. The presence of bi‐oriented steps can greatly reduce the free energy of the tBLG with matched twist angle, thus promoting the nucleation priority of tBLG. Importantly, it is shown that the 28 sets of bi‐oriented steps with twist angles of 1.5°–30° can be intentionally constructed via two‐step miscutting from bulk crystal of catalytic metals by exploring all potential combinations of bi‐steps on different epitaxial surfaces. The employment of either low‐temperature CVD growth with certain precursors or the high‐melting‐point metal substrates is suggested to against the reconstruction of bi‐oriented steps during growth. This work demonstrates an efficient scheme for the epitaxial growth of large‐area tBLG with pre‐designed twist angle, which can be potentially extended to the growth of other twist 2D materials. [ABSTRACT FROM AUTHOR]

We have synthesized thirteen novel metallomesogens based on dithiolene nickel complex showing π-acceptor properties: (o-C12OPhO)4DTNi (1), (m-C12OPhO)4DTNi (2), (p-C12OPhO)4DTNi (3), [o,m-(C12O)2PhO]4DTNi (4), [m,m′-(C12O)2PhO]4DTNi (5), [p,m-(CnO)2PhO]4DTNi (6: n = 10(a), 12(b), 14(c), 16(d)) and Cl-[p,m-(CnO)2PhO]4DTNi (7a–d). By using plarizing microscopic observations, differential scanning chalorimetry, and temperature-variable X-ray diffraction studies, the columnar liquid crystalline mesophases were established for the 6a–d and 7a–d derivatives. It was also revealed from the electrochemical measurements that each of the complexes of 1–7 showed good π-acceptor abilities. In particular, the derivatives, Cl-[p,m-(CnO)2PhO]4DTNi (7a–d), exhibit the most positive reduction potential from +0.08 to +0.07 V versus. SCE. [ABSTRACT FROM AUTHOR]

Chiral hybrid organic–inorganic metal halides combining chirality from organic components and optoelectronic properties from the inorganic moieties have attracted considerable interest from the academic community. The field is still in its early stages, especially for low-dimensional (0D, 1D) chiral hybrid organic–inorganic metal halides. Here, we report chiral zero-dimensional metal halides based on chiral nipecotic acid (NA) and tetrabromocuprate. Chiral hybrid organic–inorganic metal halides, [S-NA]2[CuBr4] and [R-NA]2[CuBr4], were synthesized from chiral NA and copper salt via the slow solution evaporation method at room temperature. The obtained crystals were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy and energy spectroscopy, Raman spectroscopy, UV-vis spectroscopy, circular dichroism (CD), thermogravimetry (TG) analysis, and differential scanning calorimetry (DSC). The single crystals were in the orthorhombic system of the chiral non-centrosymmetric space group C2221. These chiral metal halides exhibit typical zero-dimensional (0D) structures. One unit cell contains two chiral NA cations and one tetrabromocuprate ([CuBr4]2−) anion. The organic cations and inorganic anions are alternately arranged and integrated by N–H–Br hydrogen bonds. [S-NA]2[CuBr4] and [R-NA]2[CuBr4] exhibited strong CD signals with opposite values, indicating that these two hybrid organic–inorganic metal halides are enantiomers. The crystal metal halides demonstrate high thermal stability. This work provides a new strategy for designing chiral hybrid organic–inorganic metal halides in low dimensions from various biologically chiral amino acids. [ABSTRACT FROM AUTHOR]

The development of metal halides that enable multiple information storage and cryptographic security is highly desirable but remains a challenge. Here, a pair of 0D Zn(II) metal halide enantiomers ZnCl2·R/S‐2‐MP with excitation wavelength‐dependent emission and room temperature phosphorescence properties are reported. Organic ligands via N─H···Cl hydrogen bonding induce structural chirality. In order to stabilize the triplet state exciton and achieve excellent photophysical properties, the organic ligands combine with halogens to promote emission. The differences between the photophysical properties of ZnCl2·R‐2‐MP and ZnCl2·S‐2‐MP are analyzed in depth. Furthermore, combined with femtosecond transient absorption (fs‐TA) results, the long phosphorescence lifetimes may originate from the triplet state emission due to the synergistic effect between the organic components and the inorganic metal halides. The design strategy of advanced multiple anticounterfeiting technology is further extended. [ABSTRACT FROM AUTHOR]

In this research, the effect of metal electrodes and crystalline phase on gas detection of titanium dioxide (TiO 2) nanotube-based hydrogen (H 2) sensors was investigated. TiO 2 nanotubes were produced using glycerol-based electrolyte and annealed at 300 °C and 700 °C to change the anatase and rutile crystalline phases, respectively. TiO 2 nanotubes were coated by platinum (Pt), palladium (Pd), gold (Au) and silver (Ag) electrodes to fabricate metal/TiO 2 nanotubes Ti H 2 sensor devices and then the current-voltage (I–V) characteristics were investigated at room temperature. The structural properties of TiO 2 nanotubes were characterized by SEM, FE-SEM, XRD, and Raman techniques. The H 2 detection properties of the sensors were examined at the 1000 ppm - 5% H 2 concentration range. The crystal structure and metal electrodes are the main factors that affect the H 2 sensing properties of TiO 2 nanotube-based sensors. The effect of crystal forms on sensitivity was not the same as for metal electrodes. The underlying sensing mechanisms for different types of metal electrodes and crystal structures are discussed and the relevance of their sensing performance to nanotubes and electronic properties is investigated. In addition, discussion of each metal electrode and crystal structure will make important contributions to the development of H 2 sensors. The Pd-coated device annealed at 700 °C showed the best detection performance. • The synthesis of TiO 2 nanotubes by gylcerol-based anodization method. • The mean length and diameter of the nanotubes are 1.67 μm and 169 nm respectively. • The H 2 sensors were fabricated with various metal electrodes and crystal structure. • The highest H 2 sensor sensitivity was obtained with the Pd coated rutile form sensor. • The best sensor response (I H2 /I air) value was measured as 15118.7 for Pd-700 °C. [ABSTRACT FROM AUTHOR]

In this paper, we propose a simulation method to evaluate the transmittance and response time when using metal BM in the Virtual Reality display. The influence of pixel design, the voltage of metal BM ; LC type are discussed in detail. Distinguishing the contribution of the above factors on display can further pave the way to Tr improvement of LCD‐based VR application. [ABSTRACT FROM AUTHOR]

High‐entropy oxides are a material class that is currently receiving rapidly increasing attention due to the large variety in composition and the adjustable properties. Cooperative effects between different metal cations in the crystal structure in addition to entropic phase stabilization have proven beneficial for electrocatalytic applications. Most synthesis methods, however, require high synthesis temperatures and long times, and additionally only yield selected samples in good phase‐purity. Furthermore, toxic or scarce elements are often present in large amounts. Herein, a non‐aqueous microwave‐assisted solvothermal synthesis is presented as a fast and low‐temperature alternative for the fabrication of a wide range of earth‐abundant ferrites (AFe2O4). Directly crystalline, phase‐pure spinel ferrites of various compositions ranging from one to seven different A‐ions are successfully obtained after only 30 min at 225 °C. A detailed characterization of their properties in relation to their composition is performed, and they are also employed for the alkaline oxygen evolution reaction. A partial replacement of Fe by Co moreover shows the high versatility of the synthesis that also allows for the simultaneous variation of the B‐ion. [ABSTRACT FROM AUTHOR]

Improving the discharge capacities of anode materials for lithium-ion batteries without sacrificing their cycling stability and rate performance at high current densities is a big challenge due to the limited Li+ diffusion kinetics and electronic conductivity. Therefore, the introduction of dissimilar metal ions into the crystal to form doping defects can effectively improve the microstructure and ion transport kinetics, thus significantly increasing the specific capacity. As an example, a new metal ion-substituted Li 2 ZnTi 3 O 8 anode material with low agglomeration and high diffusion coefficient performs a large specific capacity of 112.4 mAh g−1 at 7.0 A g−1 and good cycle stability, as well as outstanding rate performance. The obtained electrochemical performance enhancement can be attributed to guest ions changing the microscopic crystal structure, including the influence of dopant atoms on the surrounding bulk atoms and the creation of vacancies, as well as enlarged ion transport tunnels. This strategy provides an effective way to improve the eXtreme Fast Charging of the lithium-ion battery. [Display omitted] • Li 2 Zn 0.5 M 0.5 Ti 3 O 8 nanoparticles were fabricated via high temperature solid-state technique. • High diffusion coefficient and large specific capacity at 7.0 A g−1 of the Li 2 Zn 0.5 Ni 0.5 Ti 3 O 8 was demonstrated. • This strategy of dissimilar metal ion replacement provides an effective way to improve the LIBs eXtreme Fast Charging. [ABSTRACT FROM AUTHOR]

In this study, we used the solution growth approach to successfully synthesis tricine potassium nitrate (TPN) single crystals. The phases of TPN crystals were determined by the powder X-ray diffraction (PXRD) method. The functional groups present in the crystals generated were examined using Fourier transform infrared (FT-IR) analysis. A UV-VIS-NIR examination was done between 200 and 800 nm to gauge optical transparency. The photoluminescence (PL) spectrum of TPN crystal was captured. Investigating the mechanical properties of the crystal was done using a vickers hardness tester.The thermal behaviours of the crystals formed were examined using thermal gravimetric/differential thermal analysis. A field emission scanning electron microscope was used to determine the crystal's surface shape. The TPN crystal's properties were investigated using wet etching procedures. The Kurtz–Perry technique was used to investigate the effectiveness of the developed crystals' second harmonic generation (SHG). The antibacterial activity of TPN grown crystal against various standard bacterial strains. The results show that produced TPN single crystals can be used for nonlinear optical applications and that they can also be tested for antibacterial properties to determine the material's potential applications. [ABSTRACT FROM AUTHOR]

Advanced electrocatalysts can enable the widespread implementation of clean energy technologies. This paper reviews an emerging class of electrocatalytic materials comprising holey two‐dimensional free‐standing Pt‐group metal (h‐2D‐PGM) nanosheets, which are categorically challenging to synthesize but inherently rich in all the qualities necessary to counter the kinetic and thermodynamic challenges of an electrochemical conversion process with high catalytic efficiency and stability. Although the 2D anisotropic growth of typical nonlayered metal crystals has succeeded and partly improved their atom‐utilization efficiency, regularly distributed in‐planar porosity can further optimize three critical factors that govern efficient electrocatalysis process: mass diffusion, electron transfer, and surface reactivity. However, producing such advanced morphological features within h‐2D‐PGMs is difficult unless they are specially engineered using approaches such as templating or kinetic ramification during 2D growth or controlled etching of preformed 2D‐PGM solids. Therefore, this review highlighting the successful fabrication of various porous PGM nanosheets and their electrocatalytic benefits involving smart nanoscale features could inspire next‐generation scientific and technological innovations toward securing a sustainable energy future. [ABSTRACT FROM AUTHOR]

A geometrical and topological analysis has been performed and the self-assembly of crystal structures of the Fe3(PFe3)P2-hP9, Zr3(NiAl3)Ni2-hP9, and Y3(NiAl3)Ge2-hP9 (sp. gr. P 2m, no. 189), Pr3(CoAl3)Co3(CoPr3)Ge-hP15 (sp. gr. P 2m, no.189), and Mg(Y2Cu2Mg4)Y3(CuMg3)Cu2-oP36 (sp. gr. Pmma, no 51) families has been simulated using computer methods (ToposPro software). The precursor metal clusters of the crystal structures are determined based on the algorithms of structural-graph decomposition in cluster structures. For the topological set of binary, ternary, and quaternary intermetallic compounds Fe3(PFe3)P2-hP9, Zr3(NiAl3)Ni2-hP9, and Y3(NiAl3)Ge2-hP9, which constitute 15, 580, and 64 compounds, a version of their self-assembly from templated precursor clusters Fe3(PFe3), Zr3(NiAl3)Ni2, and Y3(NiAl3)Ge2 with participation of spacer atoms P, Ni, and Ge is considered. Two chemically different seven-atom precursor clusters are established for quaternary intermetallic compounds of the Pr3(CoAl3)Co3(CoPr3)Ge-hP15 family: K7 = Pr3(CoAl3) and K7 = Co3(CoPr3), as well as Ge spacer atoms. Seven-atom precursor cluster K7 = 0@Y3(CuMg3), new-type nine-atom cluster K9 = Mg(Y2Cu2Mg4), and Cu spacer atom are established for the ternary intermetallic compound Mg(Y2Cu2Mg4)Y3(CuMg3)Cu2-oP36, which has no analogues. The symmetry and topology code of the self-assembly of crystal structures of intermetallic compounds from precursor clusters K7 and K9 is reconstructed in the following form: chain → microlayer → microframework . [ABSTRACT FROM AUTHOR]

The authors of the article conducted a research on the migration of heavy metals, such as zinc, cadmium, lead and copper, from crystal dishes using (an unused shot glass) into model solutions, namely, alcoholic drinks, deionized water at room temperature (20°С) and deionized water heated to 90°С. The content of Zn, Cd, Pb and Cu migrated to the model solutions during exposure in a crystal glass was determined by inversion voltammetry using an AVA-3 analyzer. [ABSTRACT FROM AUTHOR]

Metal halide crystals are bright but hygroscopic scintillator materials that are widely used in X‐ray imaging and detectors. Precipitating them in situ in glass to form glass ceramics (GCs) scintillator offers an efficient avenue for large‐scale preparation, high spatial resolution, and excellent stability. However, precipitating a high fraction of metal halide nanocrystals in glass to maintain high light yield remains a challenge. Herein, an ionic‐covalent hybrid network strategy for constructing GCs scintillator with high crystallinity (up to ≈37%) of BaCl2: Eu2+ nanocrystals is presented. Experimental data and simulations of glass structure reveal that the Ba2+‐Cl− clustering promotes the high crystallization of BaCl2 nanocrystals. The ultralow phonon energy (≈200 cm−1) of BaCl2 nanocrystals and good Eu reduction effect enable high photoluminescence inter quantum efficiency (≈80.41%) in GC. GCs with varied crystallinity of BaCl2: Eu2+ nanocrystals demonstrate efficient radioluminescence and tunable scintillator performance. They either outperform Bi4Ge3O14 single crystal by over 132% steady‐state light yield or provide impressive X‐ray imaging resolutions of 20 lp mm−1. These findings provide a new design strategy for developing bright transparent GCs scintillators with a high fraction of metal halide nanocrystals for X‐ray high‐resolution imaging applications. [ABSTRACT FROM AUTHOR]

Metal halide perovskites (MHPs) have attracted wide interest in spintronics. In addition, they also perform various spin–orbit coupling (SOC) strength due to their complex crystal structures. The control of SOC strength has been an increasingly prevalent topic for the manipulation of the spin degree in spintronic devices. Here, we fabricate MAPbI3 films possessing cubic crystal phase and tetragonal crystal phase with Pb vacancies. Circular photogalvanic effect (CPGE) measurements indicate that CN, representing the difference between right and left circularly polarized photocurrents, of the tetragonal structure with Pb vacancies (CN = 0.6316) is almost three orders of magnitude larger than that of the cubic structure (CN = 0.0009). Combining with the density functional theory calculations, we confirm that the strength of SOC generating the CPGE could be tuned by crystal phases of MAPbI3, and the existence of Pb vacancies could remarkably enhance the spin splitting of the band structure. Our finding provides a possible way for clarifying various puzzling SOC performances in MHPs and paves the way for spintronic device applications and circularly polarized photoelectric detectors by controlling the crystal phases and defects. [ABSTRACT FROM AUTHOR]

Magnetohydrodynamic fluid-flows attract a lot of attention in the extrusion of polymers, in the theory of nanofluids, as well as in the consideration of biological fluids. The considered problem in the paper is the flow and heat transfer of nanoand micro-polar fluid in inclined channel. Fluid-flow is steady, while nano- and micro-polar fluids are incompressible, immiscible, and electrically conductive. The upper and lower channel plates are electrically insulated and maintained at constant and different temperatures. External applied magnetic field is perpendicular to the fluid-flow and considered problem is in induction-less approximation. The equations of the considered problem are reduced to ODE, which are analytically solved in closed form. The influence of characteristics parameters of nano- and micro-polar fluids on velocity, micro-rotation and temperature fields are graphically shown and discussed. The general conclusions given through the analysis of graphs can be used for better understanding of the flow and heat transfer of nano- and micro-polar fluid, which have a great practical application. Fluids with nanoparticles innovated the modern era, due to their comprehensive applications in nanotechnology and manufacturing processes, while the theory of micro-polar fluids explains the flow of biological fluids and various types of liquid metals and crystals. [ABSTRACT FROM AUTHOR]

We used two deep learning methods, convolutional neural networks (CNN) and deep neural networks (DNN), to classify three common metal crystal structures (FCC, BCC, and HCP). The training, validation, and test datasets were created by Atomsk and Python scripts, and the data structure was transformed to meet the input requirements of CNN and DNN. To fully train and test CNN and DNN, we constructed four crystal structure datasets using random parameters. The results show that the accuracy of CNN and DNN algorithms on the test set is 100%, indicating that deep learning methods are effective for metal crystal structure classification. Compared with DNN, CNN has fewer parameters, faster training, and faster classification. It lays the foundation for further studying alloy structure detection and phase transition. [ABSTRACT FROM AUTHOR]

To determine crystal anisotropy effects at high stresses, peak states behind the plastic shock waves were examined in BCC single crystals. Using plate impact experiments, molybdenum (Mo) single crystals were shock compressed up to 190 GPa elastic impact stress along [100], [110], and [111] orientations. Laser interferometry was used to measure wave velocities and particle velocity profiles at the Mo–LiF window interface. These data were analyzed to obtain in-material quantities in the peak states. The Hugoniots for [100] and [110] orientations were comparable, but the Hugoniot for the [111] orientation was different from the other two orientations. Also, these Mo single crystal Hugoniots display differences from the polycrystalline Mo Hugoniots. Although none of the differences can be considered large, the present results demonstrate that, unlike FCC metal single crystals (Cu, Al), some anisotropy is preserved in Mo single crystal Hugoniots even at high stresses. [ABSTRACT FROM AUTHOR]

Lead-halide perovskites have attracted much attention over the past decade, while two main issues, i.e., the lead-induced toxicity and materials' instability, limit their further practice in widespread applications. To overcome these limitations, an effective alternative is to design lead-free perovskite materials with the substitution of two divalent lead ions with a pair of monovalent and trivalent metal ions. However, fundamental physics and chemistry about how tuning material's composition affects the crystal phase, electronic band structures, and optoelectronic properties of the material have yet to be fully understood. In this work, we conducted a series of density functional theory calculations to explore the mechanism that how various monovalent metal ions influence the crystal and electronic structures of lead-free Cs2MBiCl6 perovskites. We found that the Cs2MBiCl6 (M = Ag, Cu, and Na) perovskites preferred a cubic double perovskite phase with low carrier effective masses, while the Cs2MBiCl6 (M = K, Rb, and Cs) perovskites favored a monoclinic phase with relatively high carrier effective masses. The different crystal phase preferences were attributed to the different radii of monovalent metal cations and the orbital hybridization between the metal and Cl ions. The calculation showed that all Cs2MBiCl6 perovskites studied here exhibited indirect bandgaps. Smaller bandgap energies for the perovskites with a cubic phase were calculated than those of the monoclinic phase counterparts. Charge density difference calculation and electron localization functional analysis were also conducted and revealed that the carrier mobility can be improved via changing the characteristics of metal-halide bonds through compositional and, thus, crystal structure tuning. Our study shown here sheds light on the future design and fabrication of various lead-free perovskite materials for optoelectronic applications. [ABSTRACT FROM AUTHOR]