Crystal Research and Technology最新文献

The Terahertz generation is reported from novel single crystals of 2-amino-5-nitropyridinium L(+) tartrate (ANPT), grown by slow evaporation solution growth technique (SEST), using formic acid as the solvent. The preliminary analysis is conducted for the crystal to understand their structural, chemical, thermal, electrical, and optical behavior. Terahertz time domain spectroscopy (THz-TDS) is used to extract complex refractive index, dielectric constant, and conductivity of the crystal in Terahertz (THz) frequency. The Terahertz emission studies of the grown crystal is conducted and reported for the first time. ANPT crystal is found to generate THz radiation by optical rectification, with emission amplitude comparable to that of commercially used ZnTe crystals. Thus, these crystals could be a prominent candidate in designing Terahertz devices for future applications.

In recent years, Copper(I)-based inorganic halides have garnered significant interest for their exceptional optical properties. In this paper, Cs₃Cu₂Br₅ single crystals are grown by the vertical Bridgman method, resulting in large transparent single crystals ≈40 mm in length. The crystals are characterized by X-ray diffraction (XRD) and differential thermal analysis (DTA). Transmission spectra, photoluminescence (PL), temperature-dependent fluorescence spectra, X-ray excitation spectra, and photoluminescence decay time are also measured. The results indicate that the Cs₃Cu₂Br₅ single crystal exhibits good optical transmittance of 85% in the wavelength range of 250–800 nm and a large direct bandgap of 3.85 eV. The Cs₃Cu₂Br₅ single crystal displays intense broadband blue luminescence, featuring significant Stokes shifts, a microsecond-long fluorescence lifetime decay, and higher quantum yield, all attributed to self-trapped exciton emission. The temperature-dependent fluorescence spectra of the crystals are measured to analyze the luminescence mechanism. In summary, the research indicates that the Cs₃Cu₂Br₅ single crystal has certain potential applications in the field of photodetectors, light-emitting diodes, scintillators, etc.

Blue phosphorescence is confronted with significant challenges due to its need to populate and stabilize the relatively high-energy excited states. Herein, blue room temperature phosphorescence is achieved by introducing a chlorine atom with three p-orbitals to restrict the free rotation of triphenylmethane. Theoretical calculations indicate that the p-orbital of the chlorine atom promotes the spatial conjugation of three benzene rings, thereby limiting their free rotation.

In isotropic solid-state lasers, polarization control remains a challenging yet crucial aspect, especially in the absence of intrinsic birefringence. Recent studies have revealed that linearly polarized output can be realized through mechanisms such as pump polarization influence, stress- and symmetry-induced anisotropies, and frequency locking between polarization eigenmodes. This review summarizes key experimental findings and theoretical interpretations, including polarization self-selection originating from dopant site symmetry and the emergence of coherent eigenmode superposition under specific cavity conditions. While significant progress is made, most models remain confined to low-power or single-mode regimes and overlook complex behaviors in multimode, high-power scenarios. Future research should emphasize multi-physics coupling, spatiotemporal polarization diagnostics, and full-field simulation methods to bridge the gap between theoretical mechanisms and practical implementations.

Calcium phosphate-based bioceramic materials have shown tremendous potential in biomedical applications, particularly in bone repair and replacement, due to their excellent biocompatibility and osteoconductivity. However, since nucleation events occur at the atomic scale, traditional experimental methods face significant limitations in exploring the nucleation and growth mechanisms of calcium phosphate. The introduction of multi-scale computational simulation techniques can provide comprehensive understanding the nucleation mechanism and properties of calcium phosphate. This review systematically summarizes recent progress in the computational simulation of calcium phosphate nucleation and analyzes the current challenges in the field. Finally, this study further proposes that the integration of advanced computational methods, machine learning techniques, and experimental validation will enable a comprehensive understanding of the nucleation process of calcium phosphate, bridging the gap between microscopic mechanisms and macroscopic properties.

Due to the ever-increasing demand for lithium in various fields, recycling lithium from used batteries is crucial. However, the insufficient thermodynamic phase equilibrium study limited the development of lithium recovery processes. To provide a fundamental basis for the recycling of Li and Na sources from lithium battery leachate, solid–liquid equilibrium data of the Li₂SO₄-Na₂SO₄-H₂O system at different temperatures are measured based on the isothermal solution saturation method and Schreinemaker's wet residue method, which are also successfully fitted by the Pitzer model. It is found that, Na₂SO₄ zone is highly sensitive to temperature, while the zone of Li₂SO₄ remained almost unchanged when the temperature changed. Furthermore, the crystallization region of the double salt changed from one to two and then back to one as the temperature increased. Based on the thermodynamic characteristics of Li₂SO₄ and Na₂SO₄, a novel crystallization process for separating Na₂SO₄ from the mixed solution of Li₂SO₄-Na₂SO₄ is proposed, which not only enables the effective separation of high-purity sodium sulfate crystals but also enriches lithium sulfate in the solution, thereby enhancing the overall separation efficiency.

Calcium sulfate hemihydrate (CSH) crystals are a high-value-added industrial material with broad application prospects. Effective control of CSH morphology is crucial to preparing high-quality products and improving their performance. This study investigates the effect of citric acid, succinic acid, and polyacrylamide additives on the hydrothermal crystal growth and morphological evolution of CSH. CSH crystals are obtained in the presence and absence of these additives, and the products are characterized by X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). The XRD and FTIR results show that calcium sulfate dihydrate transformed into the hemihydrate form at the end of the hydrothermal process. SEM analysis reveals that citric acid led to the formation of prismatic crystals with reduced aspect ratios, while polyacrylamide resulted in thicker and irregular crystals. Additionally, fibrous need-like CSH converted into regular prismatic crystals in the presence of succinic acid. In addition, thermogravimetric analysis coupled with FTIR is performed to investigate the thermal decomposition behavior and helped to understand the dehydration kinetics and thermodynamics of the CSH. The average activation energy calculated using the Friedman method is 35.02 kJ mol⁻¹. These findings demonstrate that additive-assisted hydrothermal crystallization enables effective control over the shape parameters and morphology of CSH crystals.

Nickel-doped $��C�o_3�O_4�$ absorbing layers on glass substrates are successfully fabricated using the spray pyrolysis technique, significantly enhancing the efficiency of the multi-layer solar cell structured as SLG/Mo/ $��C�o_3�O_4�:�$ Ni/ZnS/ITO/Al. The results demonstrate the impact of Ni doping on the structural, morphological, and optical properties of $��C�o_3�O_4�.��$ X-ray diffraction (XRD) and Raman spectroscopy confirm the formation of a cubic spinel structure in the films, with crystallite sizes ranging from 11.89 to 13.11 nm. Scanning electron microscope (SEM) images reveal nearly homogeneous surfaces with enhanced porous morphology, attributed to varying dopant percentages. Energy-dispersive X-ray spectroscopy (EDX) confirms the presence of Co, O, and Ni in the films. UV–vis spectrophotometry shows improved absorbance, with the 2% Ni-doped sample identified as optimal. SCAPS-1D simulations based on these experimental results indicate an overall solar cell efficiency increase to 9.89% for the 2% Ni-doped films.