Atomic-scale gradual architecture in conductive metal-organic frameworks for microwave absorption.

Difference in charge carrier recombination among undoped, Nb-, and La-doped SrTiO3 single crystals

Structural, spectral, and nonlinear optical analysis of novel sarcosine 4-nitrophenol single crystal: Experimental and DFT insights

Synthesis and physicochemical characterization of a promising novel nonlinear optical ((E)-N1-(1H-pyrrol-2-yl)methylene)nicotinohydrazide single crystal with waveguide features

Multiscale engineering of polymer single crystals: From atomic-level order to multifunctional materials

Luminescence dosimetry remains a cornerstone in radiation measurement technology, with ongoing advancements to improve its precision, adaptability, and application scope. This work reports, for the first time, the luminescence and dosimetric properties of flux-grown undoped sapphire (Al 2 O 3 ) single crystals, with a focus on the influence of MoO 3 flux purity. Crystals were grown using fluxes of purities from 99.0% to 99.95%, and characterized using thermoluminescence (TL) and optically stimulated luminescence (OSL). Different MoO 3 purity produced crystals with different trap distribution. Both TL and OSL responses were found to depend strongly on flux purity, with a marked improvement in signal intensity and reproducibility observed up to 99.9% purity. TL signals displayed linear dose dependence with no saturation up to 62 Gy. OSL responses followed a power-law behavior, without saturation, and showed high reproducibility (< 2% variation). The crystals grown with 99.9% purity MoO 3 offered the best balance between performance and material cost. These findings highlight the potential of the flux-growth method as a cost-effective approach for producing Al 2 O 3 -based dosimetric materials, particularly for high-dose applications. Further improvements in crystal quality and sensitivity may be achieved through optimized growth conditions and targeted doping strategies. • First luminescence study of flux-grown undoped sapphire (α-Al 2 O 3 ) crystals. • Cr 3+ identified as main impurity-related emission center. • Flux purity strongly affects traps distribution and luminescent properties • MoO 3 99.9% purity offers best balance between performance and material cost.

Experimental results of growth of (Cr, Co, Fe)-co-doped ZnSe crystals, for laser applications in the range 2-5 µm, by the vertical Bridgman method under high argon pressure are described for the first time. A comparative study involving crystallographic analysis, X-ray diffraction, scanning electron microscopy, infrared spectroscopy, and other physical characterization techniques is carried out for co-doped (Cr, Co, Fe):ZnSe crystals. Growth features, morphology and optical properties of the crystals are studied and correlated with their crystal structure. The feasibility of producing large, homogeneous optical crystals with a controlled and uniform distribution of multiple activators throughout the crystal volume is also demonstrated.

Polymer lamellar crystals with highly ordered crystalline structures are ideal systems for understanding and engineering thermally conductive polymers. However, their nanometer-scale thickness, hard-to-eliminate defects, and limited lateral dimensions have impeded experimental characterization, leaving key thermal transport mechanisms unresolved. Here, we address this knowledge gap by devising a multilayer single-crystal stack for a non-contact measurement technique, combined with advanced theoretical calculations. The measured cross-plane thermal conductivity is 4W m-1 K-1 for a 12-nm-thick polyethylene lamellar single crystal, representing the highest value observed for dielectric materials in this thickness range. Theoretical analyses indicate that this value is nevertheless limited by the combined effects from boundary scattering and surface amorphization, offering critical insights for molecular design and understanding of nanoscale heat transfer in ultrathin soft materials.

Precise control over orientation and crystallinity in additive manufacturing (AM) of organic semiconductor arrays is critical for achieving high-performance organic integrated electronics. However, achieving such control in conventional AM remains particularly challenging without engineered spatial constraints due to the complex crystallization kinetics of small-molecule organic semiconductors under nonequilibrium ink deposition conditions. Here, we report a simple yet effective mask-free, pattern-free printing of high-resolution organic single-crystal arrays with controlled location, orientation, and aspect ratio. Central to this method is the establishment of a dynamic liquid-crystal area (DLCA) beneath the nozzle, which governs the kinetically coupled interplay of solute transport, solvent evaporation, and nucleation. By tuning DLCA geometry via applied voltage and speed, the random nucleation and anisotropic crystal growth is suppressed. This mechanism, supported by classical theory and transition region theory, is universally applicable to most solution-processable high-performance small-molecule organic semiconductors. The organic single crystal array exhibits highly uniform mobility, with around 12 to 15% variation, representing the most uniform organic single-crystal arrays achieved by electrohydrodynamic printing so far. In addition, the printed organic single-crystal patterns can be successfully integrated into a functional 96 organic field-effect transistor photodetector array, demonstrating their potential for information recognition and organic integrated electronics.

Achieving dynamic motions in molecular crystals with both long-range displacement and precise control remains a central challenge. Herein, we report a light-driven rolling motion in twisted single crystals of 9-cyanoanthracene, representing a new motility paradigm that combines structural asymmetry with directional actuation. Under UV irradiation, straight crystals exhibit limited bending due to anisotropic lattice expansion from localized [4 + 4] photodimerization. However, when twisted into helices, they roll rapidly and directionally toward the light source. Systematic investigations reveal that rolling is driven by a transient, light-induced shift in the center of mass, which generates torque through the misalignment of gravitational and normal forces. The rolling velocity can be finely tuned through external parameters including light intensity and incidence angle, as well as internal structural features including crystal length, width, and helical pitch. While the handedness of helicity does not affect rolling velocity under unconstrained conditions, introducing a lateral constraint with a fine wire reveals a distinct helicity-dependent deflection in the rolling trajectory. Specifically, when rolling toward the light, left-handed helices consistently deviate to the right, whereas right-handed helices deviate to the left. This helicity-biased rolling arises from asymmetric contact forces during rolling and highlights the role of contact mechanics in translating structural chirality into directional motion. This work establishes rolling as a conceptually novel mode of crystal actuation, demonstrating how structural chirality and photoreactivity can be synergistically harnessed to impart directionality to dynamic motion. Our findings lay the foundation for developing advanced smart materials with complex, programmable functionalities based on molecular crystals.

Two cadmium-gadolinium-borates, CdGdB5O10 and Cd4GdB3O10, were synthesized as polycrystalline samples, and their single crystals were also grown. Monoclinic structures in space groups P21/n and Cm were identified for the two compounds, with magnetic properties characterized through M-T and M-H measurements. The maximum magnetic entropy change (-ΔSMmax) of CdGdB5O10 reaches 23.94 J·kg-1·K-1 at 5 T and 3 K, approaching the value reported for commercial Gd3Ga5O12 under identical conditions. Cd4GdB3O10 exhibits a -ΔSMmax of 13.96 J·kg-1·K-1 at 5 T and 2 K, comparable to Dy3Ga5O12. These two cadmium-gadolinium-borates may have potential for cryogenic magnetic cooling applications due to their high -ΔSMmax, broad entropy plateau, and stable structure. Additionally, the optical and thermal properties of CdGdB5O10 were investigated.

The space microgravity environment, scarcely attainable on Earth, is considered to have a positive effect on crystal growth, especially the van der Waals layered materials with low interlayer sliding energy barriers. Here, we investigate the structure and optical/electrical properties of van der Waals InSe semiconductor cultivated in microgravity environment on China space station. Atomic-level microstructure analyses reveal that this unique environment can successfully annihilate the naturally-existing stacking faults in flexible InSe, directly activating the intrinsic sliding ferroelectricity with excellent retention stability. The corresponding ferroelectric semiconductor field-effect transistors present obviously large non-volatile memory window, high on/off ratio and excellent mobility. More essentially, they can also give superior amplified spontaneous emission with exceptionally low excitation thresholds of photons for near infrared nonlinear light sources. These findings not only present an unconventional strategy for achieving high-quality van der Waals layered single crystals like InSe but also highlight their potential for next-generation emitter-integrated computing architectures combining memory and sensor functions.

Corn rust and rice sheath blight are two major crop diseases of global importance, and hence there is much focus on solving problems regarding their control. The synthesis, isomerization, biological activity of enone oximes, the key intermediate in the synthesis of Strobilurin fungicides, and the fungicidal mechanism were researched. This study will guide the development and application of new, highly active Strobilurin fungicides. Enone oximes are synthesized using 2,6-dichlorobenzylideneacetone and hydroxylamine hydrochloride as the primary raw materials. A kinetic model for the synthesis reaction of enone oxime was established based on thermodynamic and kinetic analyses, the reaction order of 2,6-dichlorobenzylideneacetone, hydroxylamine hydrochloride and sodium hydroxide are 0.365, 0.395 and 1.085, respectively. The activation energy of the reaction was 44.32 kJ mol-1, and the apparent reaction heat was 80.94 kJ mol-1. Single crystals of E-enone oxime and Z-enone oxime were prepared, and their absolute configurations were determined by single-crystal X-ray diffraction. An isomerization strategy was developed by using gaseous hydrogen chloride as a catalyst, enabling the conversion of Z-enone oxime to E-enone oxime through a protonation-rotation mechanism. The cytochrome b protein (RsCytb) of the rice sheath blight pathogen Rhizoctonia solani was selected as the target protein, and its structure was modeled using AlphaFold3 before molecular docking. Directed synthesis of the highly active E-enone oxime was successfully achieved, and its mechanism as a highly active fragment and bioactive scaffold was clarified. E-enone oxime would be a promising bioactive fragment and active scaffold of Strobilurin fungicides. © 2026 Society of Chemical Industry.

Large sheet-like elastic crystals have vast potential applications in 2D flexible optoelectronic applications, such as information display and imaging, but this potential has been limited as the sheet-like crystal habit is not commonly observed in molecular crystals. Here, we report the crystal structure, mechanical elastic properties, mechanism of deformation, and 2D optoelectronic applications of 2,7-bis(4-methoxyphenyl)-9H-fluoro-9-one (BMeOPhFO). Elastically flexible crystals of 2D BMeOPhFO-R were obtained on a centimeter scale in both length and width. The elastic bending performance and mechanism were studied thoroughly in BMeOPhFO-R and its acicular polymorph BMeOPhFO-O, determined by micro-focused X-ray diffraction. Finally, a preliminary flexible organic light-emitting diode based on an elastic 2D single crystal of BMeOPhFO-R (bending curvature <5mm) was preliminarily prepared with low driving voltage and electroluminescence. This study will not only promote the future development of flexible molecular crystals with 2D habits, in addition to providing insights for applications in 2D flexible optoelectronics application.

Mechanoluminescent materials emit photons when subjected to mechanical stress, with the emission intensity proportional to the applied force. This property enables their use as force sensors with a direct optical readout. However, spatial resolution of the force sensing is limited by the crystal size, with thresholds near 100 μm. Seeking to overcome this limitation, we introduce stacking fault-rich, highly crystalline, monodisperse ZnS nanorods codoped with Mn and Cu (ZnS:Mn,Cu) approximately 60 × 20 nm in size. The design of these nanorods leveraged insights from the nanoscale mechanism for elastic mechanoluminescence at stacking faults that was known for micrometer-scale ZnS crystals doped with Mn. Here, ensemble impact tests confirm that the faulted ZnS:Mn,Cu nanorods indeed exhibit mechanoluminescence, where the intensity is dependent on the concentrations of both Mn and Cu. The mechanoluminescence intensity peaks at 0.15 wt % of Mn. Furthermore, a proportional increase in intensity is observed within the range of the tested Cu concentrations. The mechanoluminescence of individual nanorods with optimized dopant concentrations was investigated by using correlated atomic force and optical microscopy, with multiple force cycles delivered to individual nanorods to track force-dependent changes in the intensity of the optical emission on a single-particle level. Mechanoluminescence was detected at force amplitudes ranging between 13.9 and 100 nN, with no observable change in the nanorod morphology. Our results confirm that the introduction of stacking faults enables excitation of repeatable elastic mechanoluminescence in single nanometer crystals, which are not embedded in any matrix. This approach enables high-resolution force sensing in three dimensions in the low-nanometer range relevant to biological applications.

Reflectance spectroscopy is notoriously confounding in that the spectral response is highly dependent upon morphology. Fortunately, all such perturbations are neatly encoded by the complex refractive index. Herein, we quantitatively model the infrared reflectance spectrum of a specularly flat pressed pellet sample of the birefringent compound, sodium nitrate. Single crystals of sodium nitrate were synthesized and spectroscopically analyzed using polarization-dependent single-angle reflectance spectroscopy. Once measured and validated, the optical constants were applied to model the pressed pellet reflectance spectrum. It was evident that an average of the anisotropic refractive indices was insufficient to account for the measured pellet reflectance. The Python package pyElli was used to calculate a basis set of orientation-dependent reflection spectra spanning the distinct φ and θ Euler rotations of the uniaxial crystal. When the population of orientations was allowed to vary freely in a spectral fit analysis, the fit-deduced orientations were tightly clustered along φ = 45°, hinting at residual anisotropy in the pressed pellet sample. Conversely, an equally valid spectral fit (with marginally worse fit metric) was obtained when the population was constrained to an isotropic distribution of orientations. Subsequent non-zero cross-polarization reflectance measurements likewise suggested anisotropy in the pellet. However, both grazing-incidence wide-angle x-ray scattering and scanning electron microscopy measurements revealed that the microcrystal orientations at the surface of the pressed pellet sample were isotropically distributed. Application of the measured complex refractive indices for modeling the reflectance spectrum of the pressed pellet, and rectification of these seemingly contradictory observations will be discussed.

As a critical pretreatment process for chemical and mechanical polishing (CMP), the lapping roughness of gallium nitride (GaN) crystals directly influences the outcome of subsequent polishing and the reliability of final devices. This study systematically investigates the key factors affecting the lapping performance of GaN single crystals, focusing on abrasive type, particle size, and spindle speed, and elucidates their mechanisms in regulating material removal rate (MRR) and surface roughness. Using a micro-thickness gauge and controlled variable method, the material removal depth of the (0001) plane of GaN was accurately measured. The results show that the MRR increases with the increase in abrasive particle size within a certain range, albeit at the cost of increased surface roughness. Meanwhile, the spindle speed and MRR exhibit a positive correlation under specific conditions. Considering these lapping parameters, a balance between high MRR and controlled roughness can be achieved, providing a technical foundation for efficient and precise lapping of GaN crystals and facilitating the fabrication of GaN-based devices.

The nucleation of dislocations in sapphire of various structural perfection has been investigated by nanoindentation. The studies were carried out on crystallographic planes С (0001), a (1 1 2 0), R (0 112). In the curve of indentation of a Berkovich indenter into the single crystals, an abrupt transition from elastic to plastic deformation has been observed at a depth of about 75 nm due to the nucleation of dislocations in the initially dislocation free region under the contact. Deterioration of structural perfection results in a decrease in shear stresses under which dislocations nucleated. It is shown that the anisotropy of sapphire nanohardness is less pronounced than the static one.

Magnetoelectric (ME) materials are sought for next-generation memory, spintronics, and energy harvesting, but strong ME coupling at room temperature (RT) in single-phase systems remains rare due to the mutual exclusivity of ferroelectricity and ferromagnetism in conventional oxides. While molecular magnetoelectrics offer synthetic tunability and multifunctionality, achieving robust ME coupling above RT is still a much-coveted target. Here, we show that a homochiral molecular complex, [CoIII3DyIII(L1)6]·4MeOH (Co3Dy), exhibits a record ME coupling coefficient of 250 mV cm-1 Oe-1 at RT, enabled by magnetostriction-piezoelectric coupling. An ME nanogenerator fabricated with single crystals of Co3Dy generates a 430 mV output voltage and 0.3 μA current under a 24.2 Oe AC magnetic field, demonstrating its exceptional ME response. This work establishes single-phase molecular complexes as promising candidates for practical ME devices.

Organic laser dyes have the potential for advancing miniaturized laser technology because their vast molecular diversity offers infinite possibilities for laser design. However, it remains challenging to realize pure dye aggregate lasers due to intermolecular quenching. A universal chemical strategy for activating the optical gain in dye aggregates is highly desirable for the development of miniaturized dye lasers. Here, we propose a molecule-guided crystal engineering strategy to synthesize thermodynamically stable organic dye microcrystals capable of lasing efficiently. Multiple alkyl substituents are introduced on the organic dye molecule skeleton to transform the strong intermolecular interaction into multiple weak intermolecular interactions, which successfully activate the optical gain in dye single crystals. Different alkyl substituents lead to the formation of two kinds of microcrystals with distinct molecular packing modes and distinct geometries. Both kinds of organic dye microcrystals allow for efficient lasing. The hexagonal microcrystal with herringbone molecular packing combines large optical gain, strong cavity confinement, and high stability, which enables highly efficient and stable whispering-gallery-mode lasing. The molecule-guided crystal engineering strategy is universally applicable to diverse organic laser dye molecule skeletons and substituents, showing the potential for exploring organic microlasers with enhanced performance and functions.