Synthesis Of Single Crystals Research Articles

Synthesis, crystal growth, structural and physicochemical properties of N-methylurea benzoic acid single crystal for non-linear optical applications

The organic single crystal of N-methylurea benzoic acid (NMUB) was synthesized and successfully grown from a slow evaporation solution growth technique for the first time in literature. The structure of the NMUB single crystal was analyzed by Single crystal X-ray diffraction (SCXRD); the crystallization of the NMUB crystal was a monoclinic crystal system with the space group P21/c. The crystal structure was combined by the carboxylic groups of H- atoms in benzoic acid with protonated N-methylurea anions. The FTIR and 1H, 13C NMR chemical shifts were analyzed by distinct vibrational groups and molecular structures. The PXRD ascertains the grown crystal crystallographic planes and crystalline nature. The Hirshfeld surfaces analysis determines the theoretical inter and intra-molecular interaction with the aid of color coding. The UV-Vis NIR spectra revealed the low absorption edge, and the optical band gap was anticipated. The crystal thermal and mechanical stability was analyzed by TG/DTA, Vickers microhardness, and void volume. The laser utility limitation for the crystal was determined through laser beam irradiated LDT analysis. The third-order optical non-linear parameters were determined from the z-scan technique.

Chemical Potential-Modulated Ultrahigh-Phase-Purity Growth of Ultrathin Transition-Metal Boride Single Crystals.

Two-dimensional (2D) transition-metal borides (TMBs) are especially expected to exhibit excellent performance in various fields among electricity, superconductivity, magnetism, mechanics, biotechnology, battery, and catalysis. However, the synthesis of ultrathin TMB single crystals with ultrahigh phase purity was deemed extremely challenging and has not been realized till date. That is because TMBs have the most kinds of crystal structures among inorganic compounds, which possess generous phase structures with similar formation energies compared with other transition-metal compounds, attributing to the metalloid and electron-deficient characteristics of boron. Herein, for the first time, we demonstrate a chemical potential-modulated strategy to realize the precise synthesis of various ultrahigh-phase-purity (approximately 100%) ultrathin TMB single crystals, and the precision in the phase formation energy can reach as low as 0.01 eV per atom. The ultrathin MoB2 single crystals exhibit an ultrahigh Young's modulus of 517 GPa compared to other 2D materials. Our work establishes a chemical potential-modulated strategy to synthesize ultrathin single crystals with ultrahigh phase purity, especially those with similar formation energies, and undoubtedly provides excellent platforms for their extensive research and applications.

Synthesis, crystal structure, optical, thermoelectric, and electrochemical studies of Ba2Cu2.1(1)Ag1.9(1)Se5

We present the synthesis and characterization of single crystals and polycrystalline samples of Ba2Cu2.1(1)Ag1.9(1)Se5. A single-crystal X-ray diffraction study confirms its monoclinic structure (space group: C2/m) with lattice parameters of a = 16.0342(15) Å, b = 4.4162(4) Å, c = 9.1279(9) Å, β = 124.005(2)°, V = 535.82(9) Å3, and Z = 2. The structure of Ba2Cu2.1(1)Ag1.9(1)Se5 consists of polyanionic [∞2Cu2.1(1)Ag1.9(1)Se5]4− layers. The negative charges on these layers are counterbalanced by the filling of Ba2+ cations in the structure. The Ag and Cu atoms are statistically disordered at the same sites. The Ag/Cu atoms are bonded with four Se atoms in a distorted tetrahedral fashion. The structure also contains linear Se34− units with intermediate Se⋯Se interaction of 2.7734(14) Å. The Ba2Cu2.1(1)Ag1.9(1)Se5 can be charge-balanced as (Ba2+)2(Cu+)2.1(Ag+)1.9(Se2−)2(Se34−)1. The optical absorption study performed on a polycrystalline sample with a loaded composition of Ba2Cu2.1Ag1.9Se5 reveals a direct bandgap of 1.0(2) eV, and the indirect bandgap was found to be below 0.5 eV. The resistivity study also confirmed the semiconducting nature of the sample. The thermoelectric properties, including thermal conductivity and Seebeck coefficient, have been studied as a function of temperature. The polycrystalline Ba2Cu2.1Ag1.9Se5 has a very low thermal conductivity value of 0.46 W/mK at 673 K. The positive sign of the Seebeck coefficient values indicates the polycrystalline Ba2Cu2.1Ag1.9Se5 is a p-type semiconductor with holes as the majority of charge carriers. Further, the charge storage behavior of the material was investigated for supercapacitor application. The material delivers 76 F g−1 at 0.5 A g−1 current density in 1 M KOH electrolyte and is stable for 10,000 cycles retaining 85% capacitance.

Synthesis of centimeter-size two-dimensional hybrid perovskite single crystals with tunable, pure, and stable luminescence.

The environment-friendly synthesis and property modulation of two-dimensional organic-inorganic halide perovskite (2D OHP) single crystals with large sizes and high quality are important for the fabrication of optoelectric devices. In this work, plate-like and centimeter-size (BA)2Pb(BrxI1-x)4 (BA = n-butylammonium, x: 0-1) single crystals with high crystallinity were synthesized via the cooling crystallization method in a mixed HX (X: I, Br) acid aqueous solution. The synthesized samples were single-phase with homogenously distributed Br and I ions. The lattice structure and bandgap of (BA)2Pb(BrxI1-x)4 were both finely tuned through halide alloying. Pure photoluminescence with unitary wavelength was obtained in the mixed-halide samples compared to those of monohalides (BA)2PbI4 and (BA)2PbBr4. This is attributed to the structural homogeneity of the alloyed crystals. Moreover, the prepared (BA)2Pb(BrxI1-x)4 samples showed higher photo and thermal stability for a long duration even with ion migration. This study will be an important reference for the fabrication and property modulation of 2D OHP-based light-emitting and other optoelectric devices.

Synthesis and Characterization of Single Crystals of Cadmium Iodide as Gamma-ray Radiation Sensor

Synthesis and Characterization of Single Crystals of Cadmium Iodide as Gamma-ray Radiation Sensor

Sheet-like silicalite-1 single crystals with embedded macropores displaying superior catalytic performance

Dry-gel synthesis of sheet-like Silicalite-1 single crystals featuring intracrystalline macropores and short b-axis dimension.

Epitaxial Growth of High-Quality Monolayer MoS2 Single Crystals on Low-Symmetry Vicinal Au(101) Facets with Different Miller Indices

Epitaxial growth of wafer-scale monolayer semiconducting transition metal dichalcogenide single crystals is essential for advancing their applications in next-generation transistors and highly integrated circuits. Several efforts have been made for the growth of monolayer MoS2 single crystals on high-symmetry Au(111) and sapphire substrates, while more prototype growth systems still need to be discovered for clarifying the internal mechanisms. Herein, we report the epitaxial growth of unidirectionally aligned monolayer MoS2 domains and single-crystal films on low-symmetry Au(101) vicinal facets via a facile chemical vapor deposition method. On-site scanning tunneling microscopy observations reveal the formation of a specific rectangular Moiré pattern along the [101̅] step edge of Au(101) and along its perpendicular direction. The perfect lattice constant matching of MoS2/Au(101) along the substrate high-symmetry directions (i.e., Au[101̅], Au [010]) as well as the step-edge-guiding effect are proposed to facilitate the robust epitaxy. Multiscale characterizations further confirm the domain-boundary-free feature of the monolayer MoS2 films merged by unidirectionally aligned monolayer domains. This work hereby puts forward a symmetry mismatched epitaxial system for the direct synthesis of monolayer MoS2 single crystals, which should deepen our understanding about the epitaxy of 2D layered materials and propel their applications in various fields.

Studies on synthesis, structural, thermal, optical, spectral and mechanical properties of an inorganic strontium nitrate NLO single crystal

An inorganic NLO single crystal of strontium nitrate (SrN) was successfully grown from an aqueous solution, by slow evaporation technique at ambient temperature. Good transparent SrN crystals were obtained within 2 weeks. Various characterizations were carried out to ensure the application of the grown material. Single crystal XRD study reveals that the crystal shows a cubic structure with a centrosymmetric Pa3¯ space group. The crystalline nature of the compound was confirmed by powder X-ray diffraction. The unit cell dimension of the SrN crystal was found to be, a=b=c=7.8220 Å, and the axial angle is α =β=γ=90°. The average crystalline size of the material was 52 nm. The various functional groups associated with grown crystals have been characterized by FTIR and FT-Raman spectroscopy studies. The lower cut-off wavelength is found to be 320 nm and the band gap energy of the SrN crystal was 3.9 eV. The synthesized crystal exhibits 84% transmittance in the visible region. The grown crystals were thermally stable up to 135 °C. Various mechanical parameters such as microhardness (Hv), work hardening coefficient (n), elastic stiffness (C11), and yield strength (σy) of the grown material have been carried out by the indentation method. The nonlinear refractive index (n2), nonlinear absorption coefficient (β), and third order nonlinear susceptibility (χ(3)) were studied using the Z-scan technique, which involves open and closed aperture measurements with a continuous wave laser of 632.8 nm.

Hydrothermal synthesis of lanthanide ruthenate single crystals

A series of lanthanide ruthenates were synthesized as large single crystals using a high temperature hydrothermal method (600–650 °C, 200 MPa). In all cases, the lanthanide sesquioxides (Ln2O3) and RuO2 were used as starting materials in various ratios. A range of products containing ruthenium in a variety of oxidation states were isolated, including LnRuO3, Ln2Ru2O7, Ln2RuO5(OH), and Ln5Ru2O12, depending on the size of the rare earth and the relative ratio of starting materials. In most cases, the products were formed in good yield as high-quality single crystals. This approach provides a route to single crystals of the perovskite and pyrochlore structure types to enable advanced physical properties measurements. The study also introduces the Ln2RuO5(OH) structure type for Ru5+, and significantly expands the phase space for Ln5Ru2O12 to the later lanthanides, also as well-formed single crystals. Careful analyses of diffraction data suggest that the materials contain minimal site disorder or nonstoichiometry.

Titanium doped kagome superconductor CsV3−xTixSb5 and two distinct phases

The vanadium-based kagome superconductor CsV3Sb5 has attracted tremendous attention due to its unexcepted anomalous Hall effect (AHE), charge density waves (CDWs), nematicity, and a pseudogap pair density wave (PDW) coexisting with unconventional strong-coupling superconductivity. The origins of CDWs, unconventional superconductivity, and their correlation with different electronic states in this kagome system are of great significance, but so far, are still under debate. Chemical doping in the kagome layer provides one of the most direct ways to reveal the intrinsic physics, but remains unexplored. Here, we report, for the first time, the synthesis of Ti-substituted CsV3Sb5 single crystals and its rich phase diagram mapping the evolution of intertwining electronic states. The Ti atoms directly substitute for V in the kagome layers. CsV3−xTixSb5 shows two distinct superconductivity phases upon substitution. The Ti slightly-substituted phase displays an unconventional V-shaped superconductivity gap, coexisting with weakening CDW, PDW, AHE, and nematicity. The Ti highly-substituted phase has a U-shaped superconductivity gap concomitant with a short-range rotation symmetry breaking CDW, while long-range CDW, twofold symmetry of in-plane resistivity, AHE, and PDW are absent. Furthermore, we also demonstrate the chemical substitution of V atoms with other elements such as Cr and Nb, showing a different modulation on the superconductivity phases and CDWs. These findings open up a way to synthesise a new family of doped CsV3Sb5 materials, and further represent a new platform for tuning the different correlated electronic states and superconducting pairing in kagome superconductors.

Synthesis and Size Control of Single Crystal Ni-Rich Layered Oxide Cathodes Using Statistical Analysis-Guided Molten Salt Method

Rechargeable Li ion batteries have been widely applied in daily lives. The demand for Li ion batteries with higher energy density has been increasing especially with the thriving development of electric vehicles in the past decade. Li(Ni1−x−yMnxCoy)O2 (NMC) is one of the most successful commercial cathodes with various transition metal (Ni, Mn, and Co) ratios. Higher Ni content in the composition of NMC gives rise to higher energy density but at the price of structural and thermal stability. Recently, synthesizing single-crystal cathode particles has been extensively investigated as a strategy to enhance the stability of NMC cathodes. Most commercial NMC cathode particles possess polycrystalline structure, which is prone to induce intergranular cracking and parasitic reactions with the electrolyte upon cycling due to grain boundaries and large surface area. In contrast, single crystal NMC cathodes show higher cycling stability than their polycrystalline counterparts. However, the synthesis of single crystal normally requires higher temperatures and longer calcination duration than that of the polycrystalline counterparts for solid state synthesis. Alternatively, molten salt synthesis of single crystals is less energy-intensive and capable of tuning particle morphology and size. However, there is not yet a systematic guideline for the molten salt synthesis of single crystal Ni-rich NMC cathodes. Herein, we studied the effect of different synthetic parameters on the performance of single crystal Ni-rich NMC cathodes. We applied statistical analysis tools to correlate the synthetic conditions with cathode properties and optimized the synthetic parameters. Furthermore, we investigated the effect of single crystal size on the cathode performance. Our findings provided new insights into the synthesis and understanding of single crystal Ni-rich cathodes.

Synthesis and characterization of iQC Al13Cr2 phase single crystal

• The iQC Al 13 Cr 2 phase single crystal synthesized by Al/self-flux method. • XRD confirms needle shaped crystal which adopts monoclinic structure. • Electrical resistivity at low temperature exhibits fermi liquid behavior. • The magnetic property needs more study to declare its intrinsic to iQC Al 13 Cr 2 phase. We report the synthesis of icosaherdral quasicrystal (iQC) Al 13 Cr 2 phase single crystal via Al self-flux method. Powder X-ray diffraction study shows that it crystallizes in a monoclinic structure (space group C 2/ m ) with a unit cell of a = 25.3420 (5) Å, b = 7.6134 (5) Å, c = 11.0559 (5) Å, and β = 128.9°. Electrical resistivity of iQC Al 13 Cr 2 phase single crystal decreases with decreasing temperature, showing a metallic behavior. At low temperatures, it is reasonably fitted with T 2 dependence, implying the Fermi liquid behavior. The T 2 -coefficient A of the resistivity is 0.00182 μΩ cm/K 2 , leading to the estimated Sommerfeld coefficient γ of 13.49 mJ/molK 2 from Kadowaki-Woods relation. DC calorimetry measurements show that the specific heat divided by temperature ( C/T ) at T = 0 K is approximately 16.26 mJ/molK 2 , which is comparable with that estimated from resistivity data. We note that, unlike Al 14 Cr 2 compound with an AFM order, magnetization data of Al 13 Cr 2 phase single crystal showed is almost independent of temperature over the wide range of temperature, indicating that moments from Cr ions are screened.

An emergence of chiral helimagnetism or ferromagnetism governed by Cr intercalation in a dichalcogenide CrNb3S6

A synthesis of single crystals of chiral dichalcogenides TM3X6 (T: 3d transition metal, M: Nb or Ta, X: S or Se) remains an intriguing issue for the investigation of emergent quantum properties such as chiral helimagnetism. In this study, we investigated a correlation between the quantity of Cr intercalation x and the magnetic property in single crystals of a chromium (Cr) intercalated chiral disulfide CrxNb3S6 in order to optimize the synthesis condition for the intercalation-controlled single crystals. The magnetic properties, including a magnetic transition temperature Tc, take different values depending on the samples. We systematically grew single crystals of CrxNb3S6 with x ranged from 0.89 to 1.03 and found that the amount of the Cr intercalation x is an essential factor in controlling the magnetic properties of the grown crystals. The magnetization anomaly, which appears in the temperature dependence as evidence of the formation of chiral magnetic soliton lattice (CSL), was observed only in a narrow region of x from 0.98 to 1.03. The single crystals with x being 0.98 and 0.99 showed the CSL behavior with the highest Tc of 133 K. These results indicate that the small number of defects on the sites for T ions dramatically affects the quality of the single crystals in the synthesis of TM3S6. We also discuss the importance of synthesizing enantiopure single crystals of chiral dichalcogenides in order to observe chiral physical properties unique to chiral compounds such as magneto-chiral effect and chiral-induced spin selectivity.

Synthesis of single metallic crystal in microgravity simulated by static magnetic field

Static magnetic field is useful in processing materials with various microstructures. A self-designed gravity-assisted automatic docking device was used to study diffusion in liquid Al-Cu melts under various SMFs up to 22 T. SMF reduces the coefficient of interdiffusion (DAlCu) by damping the melt convection, which is more efficient with a horizontal SMF than a vertical SMF. A simulated microgravity is achieved when the SMF is greater than the critical 3 T. The simulated microgravity is in favor of growing a single α-Al dendrite in Al-Cu melt. The physical mechanism, which is called the diffusion-limited favored single crystal growth, is established. The present work provides a potential method in processing the single metallic crystal rapidly in the future.

Structures and Magnetic Properties of K2Pd4U6S17, K2Pt4U6S17, Rb2Pt4U6S17, and Cs2Pt4U6S17 Synthesized Using the Boron-Chalcogen Mixture Method.

A series of A2M4U6S17 (A = alkali metal; M = Pd, Pt) compounds, specifically K2Pd4U6S17, K2Pt4U6S17, Rb2Pt4U6S17, and Cs2Pt4U6S17, were synthesized using the combined boron-chalcogen mixture and molten flux crystal growth methods. The formation of rubidium- and cesium-containing analogues resulted from a in situ alkali polysulfide flux formed from alkali carbonates. The successful synthesis of single crystals of the title compounds allowed for their structural characterization by single-crystal X-ray diffraction. The structure determination revealed disorder of the alkali cations in Rb2Pt4U6S17 and Cs2Pt4U6S17, while the potassium cations in K2Pd4U6S17 and K2Pt4U6S17 were fully ordered. Magnetic measurements were performed on samples of K2Pt4U6S17, Rb2Pt4U6S17, and Cs2Pt4U6S17 that contained small amounts of paramagnetic β-US2 and diamagnetic PtS. Antiferromagnetic order was observed at TN = 9.1 K for K2Pt4U6S17. No long-range magnetic order was observed for Rb2Pt4U6S17 and Cs2Pt4U6S17. Uranium moments of 2.5, 2.6, and 2.6 μB were measured for K2Pt4U6S17, Rb2Pt4U6S17, and Cs2Pt4U6S17, respectively.

Synthesis and Physical Properties of NbMnP Single Crystals

Single crystalline NbMnP was grown by the high-temperature solution growth technique and characterized by room temperature X-ray diffraction, temperature- and field-dependent magnetization, temperature-dependent resistivity, and heat capacity measurements. NbMnP is isostructural to TiNiSi with the space group of Pnma. Physical characterizations suggest that NbMnP is metallic and goes through an anti-ferromagnet transition at around 230 K with a weak magnetic anisotropy. A small ferromagnetic component is found to be perpendicular to [010].

Centimeter-scale perovskite SrTaO2N single crystals with enhanced photoelectrochemical performance

Large-scale single crystals have potential applications in many fields, such as in ferroelectric and photoelectric energy conversion devices. Perovskite oxynitrides have also attracted attention in photoelectrochemical water splitting systems because of their high theoretical solar-to-hydrogen efficiencies. Nevertheless, the synthesis of perovskite oxynitride single crystals requires the coupling of cation exchange and ammonization processes, which is exceptionally challenging. The present study demonstrates an inorganic vapor method that provides, for the first time ever, high-quality epitaxial perovskite SrTaO2N single crystals on the centimeter scale. Assessments using Raman spectroscopy, crystal structure analysis and density functional theory determined that the conversion mechanism followed a topotactic transition mode. Compared with conventional SrTaO2N particle-assembled films, the SrTaO2N single crystals made in this work were free of interparticle interfaces and grain boundaries, which exhibited extremely high performance during photoelectrochemical water oxidation. In particular, these SrTaO2N single crystals showed the highest photocurrent density at 0.6 V vs. RHE (1.20 mA cm−2) and the highest photocurrent filling factor (47.6%) reported to date, together with a low onset potential (0.35 V vs. RHE). This onset potential was 200 mV less than that of the reported in situ SrTaO2N film, and the photocurrent fill factor was improved by 2 to 3 times.

Investigation on synthesis, growth, Hirshfeld surface and third order nonlinear optical properties of Urea-Succinic Acid single crystal: A potential candidate for self-defocusing lasing application

A wide optical band gap Urea-Succinic Acid (USA) single crystal was grown by using slow evaporation solution growth techniques. The structural analysis of grown ingot has been assessed by single crystal X-ray diffraction and high resolution X-ray diffraction techniques respectively. The various types of intermolecular interaction for the grown single crystal were visualized by Hirshfeld surface analysis using Crystal Explorer software. The photoluminescence study of grown crystal suggests major emission occurs at 460 nm which corresponds to blue light in EM spectrum. From time resolved Photoluminescence, the bi-exponential curve of major emission photons shows a defect energy state in the band structure of the grown single crystal. The self-defocusing lasing action of the grown single crystal has been studied through Nd-YAG nanosecond laser with a 532 nm wavelength. The nonlinear optical variables like nonlinear refractive index (n2) and nonlinear absorption coefficient (β) of titled compound single crystal are evaluated from Z-scan measurement. The laser damage threshold of USA single crystal is found to be 1.69 GW/cm2 for a single shot.

Synthesis of large single crystals of analcime in a template-free system

Large single ANA crystals with perfect icositetrahedral morphology have been synthesized under a simple system without templates and hydrofluoric acid.

Synthesis of CdZnTeSe single crystals for room temperature radiation detector fabrication: mitigation of hole trapping effects using a convolutional neural network

Synthesis of CdZnTeSe single crystals for room temperature radiation detector fabrication: mitigation of hole trapping effects using a convolutional neural network