Crystal Research and Technology最新文献

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.

Single crystals of the organic nonlinear compound, (2E)-2-(3,4-Dimethoxybenzylidene)-3,4-dihydronaphthalen-1(2H)-one, is synthesized and grown through slow evaporation solution approach. The crystalline structure of the grown crystals is confirmed by single-crystal X-ray diffraction measurement. The fourier transform infrared (FT-IR)and Raman (FT-Raman) studies, along with potential energy distribution analysis, confirmed the vibrational contribution to each normal mode in the molecule. Thermal studies suggest that the chalcone molecule is thermally stable up to 187^°C. The bomb calorimeter yields a calorific value of 32405 J g⁻¹, higher than that of ethanol (28895 J g⁻¹), with a relative difference of 10.83%. The material's photoluminescence (PL) spectrum illustrates emission peaks in the green region, indicating that the molecule is suitable for manufacturing green LEDs. The combined theoretical and experimental ultraviolet-visible (UV–vis) absorption spectrum demonstrated an excellent transparency area and a small optical bandgap, emphasizing the material's potential use in window optical applications. The Z-scan technique analysis with a continuous-wave laser revealed significant self-defocusing and reverse saturable absorbance effects for closed and open apertures, respectively. The optical limiting threshold value of the compound is found to be 3.18 KJ cm⁻², and the computational nonlinear optical studies predict that the title compound has superior nonlinear characteristics compared to urea, thereby suggesting that the synthesized molecule is a promising candidate for nonlinear optical applications.

Compositional distribution in a Cd_0.9Zn_0.1Te_0.97Se_0.03 single crystal grown by crucible descending method is studied. Inductively coupled plasma optical emission spectroscopy (ICP-OES) and energy-dispersive X-ray spectroscopy (EDS) reveal a pronounced cationic accumulation at the ingot tail and anionic enrichment at the seed. The segregation of either Zn (k_Zn = 1.26) or Se (k_Se = 0.83) in the ingot is hardly influenced, despite the escalating concentration imbalances between the cations and anions along the ingot length. The composition variations through the ingot length are proposed to be the result of the non-uniform intermixing of the source materials caused by buoyancy during the stepped melting of elemental precursors prior to the crystal growth process. By using poly-crystalline Cd_0.9Zn_0.1Te_0.97Se_0.03 compound as a precursor, stoichiometric Cd_0.9Zn_0.1Te_0.97Se_0.03 single crystal ingots are achieved. The approach eliminates axial compositional gradients, yielding uniform detector-grade crystals. The work clarifies precursor synthesis as a critical factor in controlling compositional defects, offering a pathway to enhance crystal quality for radiation detection applications.

Antisolvent crystallization plays a vital role in pharmaceutical applications for managing drug crystal properties and polymorphism. This study introduces an innovative method to screen and isolate the metastable form II polymorph of d-Mannitol by optimizing ethanol-mediated antisolvent crystallization in aqueous systems. Ethanol concentration x, expressed as the mole fraction in the ethanol-water solvent mixture, is varied within the range 0.030 < x < 0.235 to investigate its effect on relative supersaturation, nucleation time, and crystal morphology. Results revealed that pure form I polymorph forms at lower ethanol levels (0.030 < x < 0.177) and low relative supersaturation (0.028 ˂ σ ˂ 0.595), while higher ethanol levels (x = 0.235) and relative supersaturation (σ = 1.454) yield pure form II polymorph. Intermediate conditions (ethanol levels 0.197< x < 0.217 and relative supersaturation 0.783 ˂ σ ˂ 1.097) produced a mixture of both forms. Morphological and structural analyses are conducted using optical microscopy and powder X-ray diffraction and thermal stability is assessed with differential scanning calorimetry. The study demonstrates ethanol's significant influence on polymorphic control and crystal properties through antisolvent crystallization.

In this study, Cobalt-doped strontium-nickel spinel ferrite samples, Co_xSr_0.5-xNi_0.5Fe₂O₄, x = 0.0, 0.2, and 0.4, are successfully synthesized via the sol-gel auto-combustion method for supercapacitor applications. X-ray diffraction (XRD) investigation verifies the generation of a highly crystalline, pure cubic spinel phase with face-centered cubic structure (Fd-3m space group). Fourier transform infrared spectroscopy (FTIR) validated the spinel structure through the observation of tetrahedral and octahedral metal–oxygen vibrations, with significant shifts in vibrational bands indicating successful Cobalt incorporation and cation redistribution. Field emission scanning electron microscopy (FESEM) images exposed the development of highly porous microstructures, with the x = 0.4 sample exhibiting the most uniform particle distribution and maximum porosity, beneficial for ion transport. Electrochemical analysis through cyclic voltammetry (CV) demonstrated that the x = 0.4 composition exhibited the largest enclosed area in the CV curves, indicating superior charge storage capability. Galvanostatic charge–discharge (GCD) measurements further confirmed that the x = 0.4 sample delivered the highest specific capacitance value of 12364.341 F g⁻¹ at lower current densities, highlighting its excellent electrochemical performance. Overall, the Co_xSr_0.5-xNi_0.5Fe₂O₄ sample with x = 0.4 composition emerges as the most promising candidate for high-performance supercapacitor electrodes, owing to its enhanced structural integrity, favorable porosity, and superior electrochemical behavior.

Pharmaceutical cocrystal technology has gained significant attention for its potential to enhance drug performance, particularly by improving solubility and bioavailability. Various preparation methods, characterization techniques, and screening tools are developed, including Hansen Solubility Parameters (HSP), COSMO-RS theory, Molecular Electrostatic Potentials (MEPs) for identifying hydrogen bond donors and acceptors, molecular dynamics simulations (MD), and machine learning (ML) techniques. These predictive tools facilitate virtual screening, expediting the discovery of promising cocrystals. In addition to solubility enhancement, cocrystal technology plays a crucial role in the drugs separation. Recent studies have explored enantiospecific and diastereomeric cocrystals, among other strategies, to improve the purity and efficacy of pharmaceutical compounds. These innovations offer valuable solutions for optimizing drug performance and further advancing the application and exploration of cocrystal technology in drug development.

Microwave has triggered huge interests for its efficient control of precipitation process. However, quantitative study of the coupling effect of thermal radiation and electromagnetic radiation of microwave on precipitation is limited. In this paper, the effect of microwave energy input on precipitation is studied experimentally and numerically at different temperature firstly. Sauter mean diameter of crystal products (d₃₂) is found to decrease with higher inflow concentration and increase with stronger microwave energy intensities (E) and higher temperature. In order to assess the influence of temperature and microwave energy input on nucleation, growth, aggregation, and crystal breakage, a population balance model coupled with empirical precipitation kinetics is performed. These kinetic parameters, including nucleation rate constant (k_n) and exponent (n), growth rate constant (k_g) and exponent (g), aggregation efficiency (Ψ_ag), and breakage rate constant (k_br) are fitted against experimental data. It is found that the electromagnetic effect of microwave can improve nucleation, crystal growth, and aggregation without breaking crystal product. Meanwhile, the thermal effect of microwave can enhance crystal growth, aggregation, and breakage while restrain nucleation. By choosing proper temperature, microwave provides a promising approach to produce larger crystals without additional risk of extra nucleation and crystal breakage.