Crystal Growth & Design最新文献

In this work, two functional two-dimensional (2D) Zn(II) metal–organic frameworks (Zn-MOFs), {[Zn(NDC)(CEbpy)]·H₂O}_n (1) and {[Zn(HBTC)(CV)_0.5(H₂O)]·0.5(CV)·6H₂O}_n (2), were synthesized using two viologen-carboxylate ligands (CEbpy = 1-carboxyethyl-4,4′-bipyridine; CV = N,N′-4,4′-bipyridiniodipropionate) in the presence of secondary linkers (H₂NDC = 1,4-naphthalenedicarboxylic acid; H₃BTC = 1,3,5-benzenetricarboxylic acid). Owing to the successful construction of the donor–acceptor (D–A) system, both Zn-MOFs exhibited excellent electron-transfer photochromic properties, and their photoproducts remained stable in air for several days. Additionally, compounds 1 and 2 exhibited potential for photocontrolled luminescence and demonstrated clear and legible printing capabilities, making them suitable for use as light-controlled switch and inkless erasable printing media.

This paper focuses on the enhancing effect of doped Bi³⁺ and Ce³⁺ ions on the specific Faraday rotation angle of the terbium iron garnet (TIG) magneto-optical crystal. By means of structural design, a large-radius Ce³⁺ is doped into the dodecahedron sites of the bismuth-doped terbium iron garnet (Bi:TIG) structure. The cell volume of the crystal is enlarged to accommodate higher content of Bi³⁺ and Ce³⁺. Centimeter-sized, high-quality cerium- and bismuth-codoped terbium iron garnet (Ce,Bi:TIG) and Bi:TIG crystals were successfully grown by the top-seeded solution growth (TSSG) method using a lead-free Bi₂O₃–Fe₂O₃ flux. Among these as-grown crystals, the transmittance of Ce_0.13Bi_0.60Tb_2.27Fe_4.85Ga_0.15O₁₂ is 70.7% and the specific Faraday rotation angle is up to −800 deg cm^–1 at 1550 nm. The Faraday rotation temperature coefficients (FTC) and the wavelength coefficients (FWC) of Ce_0.13Bi_0.60Tb_2.27Fe_4.85Ga_0.15O₁₂ are −1.72 × 10^–3 K^–1 and 1.40 × 10^–3 nm^–1, respectively. Ce,Bi:TIG crystal is expected to be applied in magneto-optical isolators at 1550 nm.

Plastic crystals are a unique class of dynamic crystalline materials that combine long-range order with partial molecular mobility, resulting in remarkable mechanical properties, such as plasticity and flexibility. These crystals have emerged as promising candidates for advanced flexible devices and pharmaceutical applications. In this study, we investigate the plastic behavior of 3-bromo-5-chlorobenzoic acid (3B5CBA), a globular halogenated aromatic compound. Crystals of 3B5CBA grown via a fast evaporation technique exhibited plastic bending when stressed along the (001) plane. Thermal analysis of crystals revealed a sublimation onset at approximately 70 °C and a melting point of 195.3 °C. Single-crystal X-ray diffraction (SCXRD) analysis and energy framework calculation revealed strong 2D sheet-like interactions parallel to the (001) plane (−299.9 kJ/mol) and weaker interlayer C–Br···O interactions (−79.6 kJ/mol) forming low-energy slip planes. Nanoindentation on the (001) face confirmed homogeneous plastic deformation with a moderate hardness of 217.48 ± 19.87 MPa and a Young’s modulus of 2.94  ± 0.35 GPa. Furthermore, shape analysis using Hirshfeld surface parameters showed high globularity (G = 0.808) and low asphericity (Ω = 0.108). Together, these results showed that 3B5CBA being an organic aromatic compound with a nearly globular shape, hydrogen and halogen synthon-forming functional groups on its periphery can show long-range disordered crystal structure, sublimation ability, and irreversible plastic deformation, offering new insights into the design of aromatic plastic molecular solids.

SnCl₂ and CdCl₂-assisted doping was employed to tune the defect landscape and functional properties of SnSe crystals synthesized by direct vapor transport. Structural and compositional analyses confirm successful dopant incorporation, where SnCl₂ passivates Se vacancy-related defects and expands the lattice, while CdCl₂ induces controlled lattice distortion via Cd²⁺ substitution. These effects tune the optical band gap from 1.27 eV in pristine SnSe to 1.49 and 1.38 eV in SnCl₂:SnSe and CdCl₂:SnSe, respectively. Temperature-dependent transport measurements reveal the elimination of the positive TCR behavior observed in undoped SnSe and the establishment of stable thermally activated conduction in the doped systems. Hall measurements indicate a transition from p- to n-type conduction, accompanied by an increase in the electron concentration, consistent with vacancy passivation and defect compensation. Both doped crystals exhibit modest yet measurable improvements in photocurrent and noise characteristics, while photocatalytic studies show better methylene blue degradation efficiencies, with SnCl₂:SnSe outperforming CdCl₂:SnSe. These results demonstrate that chloride-based doping tailors SnSe for better optoelectronic and photocatalytic performance effectively.

Cocrystal engineering has become an essential strategy in materials science, enabling the design of new solid-state systems through the rational combination of organic components guided by noncovalent interactions. In this study, the cocrystallization of a bis-pyridyl-azine substrate with three different coformers, namely, 1,3,5-triiodo-2,4,6-trifluorobenzene, 1,2-diiodotetrafluorobenzene, and 4,4′-biphenol, led to the formation of five new cocrystal systems. The supramolecular architectures of these materials were investigated with a focus on the role of halogen bonding and hydrogen bonding in crystal packing. All observed noncovalent interactions were investigated using density functional theory (DFT) calculations carried out with the ωB97XD functional and the def2-TZVPP. The results emphasize the influence of molecular recognition in the self-assembly process and reveal how halogen and hydrogen bonds act as key driving forces in the formation and stabilization of these cocrystals.

Five new cocrystals formed from a bis(pyridyl)azine derivative and halogen- or hydrogen-bond donors are reported, showcasing how subtle electronic effects and packing preferences govern the balance between I···N, I···F, I···I, O−H···N, and C−H···F interactions, enabling the fine-tuning of distinct supramolecular architectures.

A novel high-entropy laser crystal of 30 at. % Er:GdLuYSGG was grown by the Cz method. The crystal exhibits high crystalline quality, evidenced by an X-ray rocking curve FWHM of 0.007°. The thermal expansion coefficient and thermal conductivity are determined to be 1.52 × 10^–5 K^–1 and 4.10 W m^–1 K^–1, respectively. A broadened fluorescence band around 2760–2840 nm is observed and attributed to the lattice distortion effect of the high-entropy crystal, indicating the Er:GdLuYSGG crystal is beneficial for realizing tunable or ultrafast lasers. By a 973 nm LD end-pumping, a continuous-wave 2.8 μm laser is achieved with a maximum output power of 1062 mW, corresponding to a slope efficiency of 17.99%. The M_x²/M_y² factors are 1.35 and 1.37, suggesting a high laser beam quality. The results imply that the high-entropy Er:GdLuYSGG crystal is a promising broadband gain medium for high-performance 2.8 μm mid-infrared laser, which might be particularly suited for applications in space radiation environments.

A novel high-entropy Er:GdLuYSGG crystal was successfully grown. The absorption and fluorescence bands were both broadened, an enhanced continuous-wave 2.8 μm laser was achieved with a maximum output power of 1062 mW. The high-entropy Er:GdLuYSGG crystal is a promising broadband gain medium for high-performance 2.8 μm mid-infrared laser.

Due to its ultrawide bandgap and robust physical properties, β-Ga₂O₃ is a promising candidate for solar-blind UV photodetectors. However, conventional fabrication methods are often costly and complex. In this study, we demonstrate a cost-effective spin-coating technique to fabricate Sn-doped β-Ga₂O₃ thin films and systematically investigate the effect of Sn concentration on their structural, optical, electrical, and photodetection properties. The results show that controlled Sn doping effectively enhances device performance by tuning the material’s optoelectronic characteristics. Sn-doped β-Ga₂O₃ thin films were deposited at room temperature onto sapphire substrates using spin coating, with tin concentrations systematically varied from 0 to 20 wt %. X-ray diffraction analysis confirmed that all films crystallized in the monoclinic β-Ga₂O₃ phase with a nanocrystalline structure. The optical results showed high transmittance in the visible region and a progressive narrowing of the bandgap with increasing concentration of Sn doping. Electrical characterization revealed that the carrier concentration, electrical conductivity, and electron mobility increased with Sn doping up to 15 wt %. However, at 20 wt % Sn, a reduction in mobility was observed, likely due to enhanced carrier scattering or the introduction of defect states. Furthermore, metal–semiconductor–metal (MSM) photodetectors were fabricated to evaluate the influence of increasing Sn wight percentage on device performance. The results demonstrated that with increasing Sn concentration, UV responsivity, detectivity, and response speed were significantly enhanced, highlighting the potential of Sn-doped β-Ga₂O₃ thin films for high-performance and cost-effective optoelectronic applications.

To address limitations in real-time 3D morphology acquisition for crystal growth kinetics, this study pioneers an ultrasound–visual dual-modal monitoring system integrating stereoscopic imaging, ultrasonic attenuation, and molecular simulation. The system achieves 37% lower edge-length error in 3D reconstruction vs 2D projection and enables real-time concentration tracking via a PCA-GA-BP neural network (R² = 0.9998). Kinetic experiments (n = 50) demonstrate that the (200) plane grows 14.5% faster than (111) (0.544 vs 0.475 μm/min) with higher temperature sensitivity (18% enhancement at 323.15 K). Molecular simulations reveal stronger water adsorption on (111) planes (−41.26 vs −10.84 kcal/mol), while the Modified Adsorption Energy (MAE) model corrects solvent-accessible area effects: the (111) plane proportion decreases from 67.14% to 47.44%, whereas (200) increases to 52.56%, aligning with experimental habits. This integrated methodology provides cross-scale insights for inorganic salt crystallization mechanisms and industrial process optimization.

γ-CuI with zinc blende structure has emerged as a next-generation electrical material, but its current two-step chemical vapor deposition (CVD) method still faces problems including high I-residue/vacancy and low film uniformness. The strategy of one-step CVD using a single-source precursor (SSP) could be a feasible solution. In this work, a tetra-nuclear cubane cluster Cu₄I₄(TMOP)₄ (TMOP = tris(4-methoxyphenyl)phosphine) was constructed and used as SSP in γ-CuI deposition first. As indicated by structural analysis of this SSP, the introduction of methoxy on the p-position of PPh₃ and the absence of π–π/C–H···π interactions can improve its solubility in organic solvent. More importantly, cuprophilic interactions and fluctuant Cu–I bonds can be beneficial for fracture and reconstitution on the substrate surface during the CVD process. Upon optimization of the substrate, deposition sites, gas velocities, and deposition temperatures, the continuous γ-CuI film with an ultralow roughness (R_q = 4.60 nm) under optimal CVD conditions has been obtained, which has been characterized by XRD, SEM, AFM, XPS, and Raman spectra. The {111} preferential growth mechanism of this γ-CuI has been clarified: the anchoring of Cu₄I₄ clusters by the size-matched SnO₂(110) surface, the Cu–I fracture/reconstitution restricted by cuprophilic interactions, and final growth along the {111} direction. This one-step CVD process using the copper iodide cubane cluster as SSP could pave a new way for the large-scale production of high-quality γ-CuI films.