Crystal Research and Technology最新文献

Transition-metal dichalcogenides (TMDs) are nanostructures renowned for their unique lattice properties, offering significant potential in nanotechnology and materials science. In this study, we introduce 1D cellular automata (CA) framework to simulate the structural growth of TMDs on a 2D grid. By algorithmically encoding the lattice dynamics into CA rules, we replicate the spatial evolution of TMD architectures. We analyze the periodicity inherent in these CA-generated structures, reflecting the ordered growth observed in TMDs. Furthermore, we investigate the reversibility of the CA rules to examine whether the growth process can be computationally reversed, which is an essential property for theoretical modeling and nanofabrication. The entropy graphs characterize the regularity and complexity of the evolving patterns.

Although numerous studies related to liquid crystal polymer (LCP) have been carried out, there is a notable absence of data-driven evidence highlighting influential journals, leading countries, prominent institutions, and research tendency. To fill this gap, this study employs bibliometric methods to statistically examine the relevant publications. The annual publication output has shown a significant upward trend, with the number of publications in 2024 reaching a historic peak of 68, nearly quadruple the number in 2004. Among the Web of Science categories, “Materials Science Multidisciplinary” accounted for the highest proportion (33.6%). The bibliometric indicators confirm that China, the USA, and the Netherlands are leading countries, while Eindhoven University of Technology and Fudan University signified their prominent positions with the H-index of 20 and 19, respectively. The frequency of keyword occurrences over different periods suggests that the research on LCP has evolved from “basic structure and performance” to “device fabrication”, followed by “stimuli-responsive actuation”, and ultimately to “chiral photonic multifunctional integration”. The findings of this analysis are intended to help delineate the intellectual structure of the field, trace the evolution of research themes, and offer valuable insights and potential directions for future research.

Dye-sensitized solar cells (DSSCs) are attracting significant attention as alternatives to expensive semiconductor-based solar cells due to their economical and straightforward manufacturing processes. However, initiatives are underway to substitute counter electrodes (CE) in dye-sensitized solar cells (DSSCs), which traditionally utilize noble metal platinum (Pt). This study involved the preparation of tungsten diselenide (WSe₂) films using the magnetron sputtering technique, which are subsequently used as counter electrodes in a DSSCs system. Different Cu ratios are included in the WSe₂ films to enhance electron conductivity and the bonding strength between the active material and substrate. Owing to its good electrochemical properties and superior surface area, the device utilizing Cu-WSe₂ CE delivers a power conversion efficiency (PCE) of 5.54%, exhibiting improved photovoltaic parameter metrics, thereby competing with Pt (6.22%). This study elucidated the synergistic interaction between WSe₂-based CEs and electrolytes, which is crucial for achieving enhanced electrocatalytic activity in the iodide redox process. Consequently, we believe in providing this material as a viable alternative to improve energy conversion in future industrial applications.

This study examines the impact of supersolidus solution heat treatment (SSHT) on the suppression of topologically close-packed (TCP) phases and the regulation of γ′ phase size in two CMSX-4 nickel-based single-crystal superalloys with varying Re contents (3% and 5%). The results indicate that increasing the solution termination temperature or extending the holding time effectively suppresses TCP phase formation. In the 5% Re alloy, TCP phases that form after 35 h at 1340°C are eliminated by either extending the holding time to 50 h or raising the temperature to 1350–1360°C. The average γ′ phase size is influenced by the melting zone. In the 3% Re alloy, it shows little variation. While in the 5% Re alloy, it initially decreases, then increases at 1340°C, reaching a minimum of approximately 0.36 µm after 35 h. At 1350°C, the size refines from 0.41 to 0.34 µm between 15 and 35 h, but subsequently coarsens and spheroidizes to approximately 0.52 µm after 50 h. Higher temperatures expedite the process of spheroidization. This research emphasizes that SSHT effectively suppresses TCP phases. Nonetheless, excessive temperature or prolonged duration leads to spheroidization of the γ′ phases due to excessive melting.

For heteroepitaxial single-crystal diamond growth, iridium is recognized as the optimal nucleation layer due to its unique carbon-saturated precipitation mechanism that facilitates the formation of highly oriented and dense diamond nuclei. This study employed magnetron sputtering to deposit iridium on (11-20) a-plane sapphire substrates, systematically investigating the effects of deposition temperature, sputtering power, and rapid high-temperature annealing on the orientation, surface morphology, and film quality of Ir. Experimental results demonstrated that (100)-oriented Ir films are successfully achieved at a deposition temperature of 780°C with 125 W sputtering power. Subsequent rapid thermal annealing at 1000°C significantly improved the crystalline quality, evidenced by the reduction of FWHM for Ir (002) XRD rocking curve from 436 to 323 arcsec. TEM analysis confirmed the single-crystal nature of Ir films with minimal lattice strain. This achievement of high-quality Ir films establishes a crucial foundation for optimizing the quality of subsequent heteroepitaxial single-crystal diamond growth. The fabrication of high-quality, highly-oriented iridium films serves as an essential prerequisite for the successful nucleation and growth of high-quality heteroepitaxial diamond. This study demonstrates the deposition of Ir on 2-inch sapphire, thereby representing a critical step toward the realization of heteroepitaxial single-crystal diamond at the 2-inch scale and beyond.

To enhance the hygroscopic properties of palmatine chloride (PCl), a novel salt cocrystal is synthesized through the combination of water-assisted grinding and solvent evaporation methods applying p-coumaric acid (CA) as the cocrystal co-formers. Single crystal X-ray analysis revealed that four chloride ions, two water molecules, and two coumaric acid molecules interacted via hydrogen bonding to form the typically basic structural units, which connected through weak interactions to form 2D planar structures in the boc plane. The palmatine molecules are arranged vertically between the planes and continuously stacked to form a 3D crystal structure. In comparison to PCl, the hygroscopic stability of the PCl-CA salt cocrystal is notably improved, indicating that CA molecules occupied the binding site between chloride ions with strong hydration ability and external water molecules in the self-assembly of the salt cocrystal, thus reducing the binding affinity of PCl-CA to water. Although the hygroscopic stability of PCl-CA is considerably enhanced compared to PCl itself, its solubility is regrettably lower, warranting further investigation. Notably, the introduction of CA molecules significantly boosted the antibacterial potency of the PCl-CA salt cocrystal in vitro. The aforementioned experimental outcomes are corroborated by theoretical calculations, encompassing frontier molecular orbitals analysis and Hirshfeld surface analysis.

The DFT study of Alanine Maleate and Alanine Fumarate NLO crystals assisted by B3LYP/6-31+G^* in the gas phase investigates the optimized geometry, Mulliken charges, Frontier Molecular Orbitals (FMO), Hyperpolarizability, and Vibrational spectra of the molecules. The Natural Bond Orbital analysis of Alanine Maleate and Alanine Fumarate sheds light on the hyperconjugative interactions of LP N3 → σ* H5─O25 and LP N3 → σ^* O23─H24, suggesting the existence of the hydrogen bond between N3─H5 and N3─H24, respectively. The analysis of Quantum Theory of Atoms in Molecules (QTAIM) with the help of Multiwfn revealed the type of hydrogen bonding on the basis of topological parameters at the Bond Critical Points. The Reduced Density Gradient study has facilitated a pictorial depiction of the strong hydrogen bonding of N─H and other Non-Covalent Interactions (NCI) present within the molecules. The kinetic stability of the material has been sufficiently indicated by the HOMO-LUMO energy gap. The UV spectra obtained from TD-DFT highlighted the transparency of Alanine Maleate and Alanine Fumarate above 300nm in the UV region, with a cut-off wavelength around 250nm. The Molecular Electrostatic Potential Surface displayed the electrophilic sites of Alanine Maleate and Alanine Fumarate. The theoretically predicted IR and Raman spectra demonstrated the characteristic vibrations of the functional groups, including the N─H hydrogen bonds. The computed first-order Hyperpolarizability value of Alanine Maleate and Alanine Fumarate is 3.9 and 1.64 times that of Urea, quoting its prominent NLO efficiency.

The co-crystallization behavior of the energetic compound 3-nitro-1,2,4-triazol-5-one (NTO) with planar heteroaromatic coformers is examined to assess its impact on molecular interactions and thermal stability. NTO is co-crystallized with 3-aminopyrazole (APRZ), 1,2,4-triazole (TRZ), 4-amino-1,2,4-triazole (ATRZ), and imidazole (IMD) at specific molar ratios in polar protic solvents. The crystalline structures obtained are analyzed through single-crystal X-ray diffraction, nuclear magnetic resonance (NMR) spectroscopy, and infrared (IR) spectroscopy techniques. Thermogravimetric analysis (TG) is used to evaluate the effect on explosive characteristics. Single crystal X-ray diffraction (SCXRD) data demonstrate that the co-crystals displayed unique lattice structures in contrast to the pure components, suggesting notable intermolecular interactions between NTO and the coformers. Structural analysis reveals that planar NTO molecules are organized into layers parallel to the planar configurations of APRZ, TRZ, ATRZ, and IMD. Instead of π–π interactions, it is observed that strong hydrogen bonds between the molecular rings serve as the primary driving force for co-crystal formation. The thermogravimetric analysis reveals that the co-crystals underwent disintegration close to the melting point of NTO, subsequently decomposing and exhibiting thermal behavior characteristic of two distinct substances.