Growth Of Large Crystals Research Articles

Ba2Si3P6: 1D Nonlinear Optical Material with Thermal Barrier Chains.

A novel barium silicon phosphide was synthesized and characterized. Ba2Si3P6 crystallizes in the noncentrosymmetric space group Pna21 (No. 33) and exhibits a unique bonding connectivity in the Si-P polyanion not found in other compounds. The crystal structure is composed of SiP4 tetrahedra connected into one-dimensional double-tetrahedra chains through corner sharing, edge sharing, and covalent P-P bonds. Chains are surrounded by Ba cations to achieve an electron balance. The novel compound exhibits semiconducting properties with a calculated bandgap of 1.6 eV and experimental optical bandgap of 1.88 eV. The complex pseudo-one-dimensional structure manifests itself in the transport and optical properties of Ba2Si3P6, demonstrating ultralow thermal conductivity (0.56 W m-1 K-1 at 300 K), promising second harmonic generation signal (0.9 × AgGaS2), as well as high laser damage threshold (1.6 × AgGaS2, 48.5 MW/cm2) when compared to the benchmark material AgGaS2. Differential scanning calorimetry reveals that Ba2Si3P6 melts congruently at 1373 K, suggesting that large single crystal growth may be possible.

Growth of large and high quality CsLiB6O10 crystals from self-flux solutions for high resistance against UV laser-induced degradation

Crystal growth of CsLiB6O10 (CLBO) was conducted by using various self-flux solutions. We evaluated the degradation under 266 nm irradiation, with measured intensity of scattered green light. The CLBO crystal grown from Li-poor composition had the highest resistance to the laser UV-induced degradation compared with the other composition. In addition, the scattering of the green laser light was low. Furthermore, we also grew a larger CLBO crystal without cracks and inclusions from Li-poor flux composition using a larger crucible, which shows that this method is highly suitable for growing large and high quality CLBO crystals.

Benefits of the Hydrophobic Surface for CH3NH3PbI3 Crystalline Growth Towards Highly Efficient Inverted Perovskite Solar Cells.

In inverted perovskite solar cells (PSCs), high-quality perovskite film grown on hole-transporting material (HTM) with pinhole-free coverage and a large grain size is crucial for high efficiency. Here, we report on the growth of pinhole-free and large grain CH3NH3PbI3 crystals favored by a hydrophobic small molecular HTM, namely, 4,4′-Bis(4-(di-p-toyl)aminostyryl)biphenyl (TPASBP). The hydrophobic surface induced by TPASBP suppressed the density of the perovskite nuclei and heterogeneous nucleation, thus promoting the perovskite to grow into a dense and homogeneous film with a large grain size. The CH3NH3PbI3 deposited on the TPASBP exhibited better crystallization and a lower trap density than that on the hydrophilic surface of indium tin oxide (ITO), resulting in a significant reduction in carrier recombination. Combined with the efficient hole extraction ability of TPASBP, a high efficiency of 18.72% in the inverted PSCs fabricated on TPASBP was achieved.

In situ real-time annealing of ultrathin vertical Fe nanowires grown by focused electron beam induced deposition

Focused Electron Beam Induced Deposition is a consolidated technique for the growth of three-dimensional (3D) nanostructures. However, this single-step nanofabrication method requires further efforts to optimize simultaneously dimensional and compositional properties, in particular for deposits with a high aspect ratio. More specifically, ferromagnetic 3D nanowires (NWs) with diameters in the sub-50 nm regime and high metallic contents up to 95 at. % attract great interest to improve the final performance of magnetic nanodevices such as magnetic tips for scanning probe microscopy. In this work, we report on real-time monitoring during chemical purification and structural crystallization processes of ultra-narrow 3D Fe NWs (<50 nm in diameter achieved) by post-growth in situ annealing in a transmission electron microscope. NW heating up to 700 °C in very high vacuum reveals the local increase of the metallic content along the entire NW length concomitant with the growth of large Fe single crystals from initially amorphous compounds. A metallic purity of 95 at. % is observed in several regions, dramatically boosting the initial Fe content of 40 at. %. The real-time in situ tracking of 3D nanostructures during thermal annealing is a key element to design and optimize novel purification processes for the fabrication of customized components to be integrated in spintronic, logic and sensing devices.

Transport and crystallization of NaCl solution in porous silicate materials

Salt damage is the most common and severe type of damage to silicate cultural relics. The transport and distribution of NaCl solution in porous SiO2 and porous silicate materials as well as its crystallization and destructive effects on the silicate samples were analyzed using low-field nuclear magnetic resonance (NMR), X-ray micro-computed tomography (micro-CT), three-dimensional digital microscopy with a large depth-of-field, and polarized light microscopy. The migration of solution was more active in the capillary pores smaller than 4.5 mm, and the interconnected pores transport the solution directly from the interior to the surface via capillary action. Salt crystals first grow and accumulate in the corner pores, which have a large surface area and exert an adsorption effect on the surrounding solution. This results in transport of the surrounding solution to the crystallization region on the edges, contributing to the growth of large crystals. Movement and turning of the particles occurred during the transitions of the porous silicate particles or Al2O3 particles caused by crystallization of the soluble salts. This was likely associated with the expansion effect caused by the growth of small-sized crystals within particles in the crystalline region, the layer-by-layer accumulative growth effects of large-sized crystals formed on the interface between the solid phase and the liquid phase in the capillary pores, and the attraction and contraction forces in the dehydration stage. These effects accelerated the destruction of the bonds between the silicate particles. The crystallization of salt solution on the interior morphology and displacement of porous materials were observed directly, which provides a scientific rationale for discussing the change of the main forces in the destruction of silicate particles.

Single-Crystal Growth of Metallic Rare-Earth Tetraborides by the Floating-Zone Technique

The rare-earth tetraborides are exceptional in that the rare-earth ions are topologically equivalent to the frustrated Shastry-Sutherland lattice. In this paper, we report the growth of large single crystals of RB 4 (where R = Nd, Gd → Tm, and Y) by the floating-zone method, using a high-power xenon arc-lamp furnace. The crystal boules have been characterized and tested for their quality using X-ray diffraction techniques and temperature- and field-dependent magnetization and AC resistivity measurements.

Insight into the rapid growth of graphene single crystals on liquid metal via chemical vapor deposition

Previous reports about the growth of large graphene single crystals on polycrystalline metal substrates usually adopted the strategy of suppressing the nucleation by lowering the concentration of the feedstock, which greatly limited the rate of the nucleation and the sequent growth. The emerging liquid metal catalyst possesses the characteristic of quasi-atomically smooth surface with high diffusion rate. In principle, it should be a naturally ideal platform for the low-density nucleation and the fast growth of graphene. However, the rapid growth of large graphene single crystals on liquid metals has not received the due attention. In this paper, we firstly purposed the insight into the rapid growth of large graphene single crystals on liquid metals. We obtained the millimeter-size graphene single crystals on liquid Cu. The rich free-electrons in liquid Cu accelerate the nucleation, and the isotropic smooth surface greatly suppresses the nucleation. Moreover, the fast mass-transfer of carbon atoms due to the excellent fluidity of liquid Cu promotes the fast growth with a rate up to 79 µm s–1. We hope the research on the growth speed of graphene on liquid Cu can enrich the recognition of the growth behavior of two-dimensional (2D) materials on the liquid metal. We also believe that the liquid metal strategy for the rapid growth of graphene can be extended to various 2D materials and thus promote their future applications in the photonics and electronics.

Influence of ZrO2 Nanoparticles on the Microstructural Development of Cement Mortars with Limestone Aggregates

In this research, the effect of the addition of zirconium oxide-synthesized nanoparticles on the microstructural development and the physical–mechanical properties of cement mortars with limestone aggregates was studied. Zirconia nanoparticles were synthesized using the co-precipitation method. According to XRD analysis, a mixture of tetragonal (t) and monoclinic (m) zirconia phases was obtained, with average crystallite sizes around 15.18 and 17.79 nm, respectively. Based on the ASTM standards, a mixture design was obtained for a coating mortar with a final sand/cement ratio of 1:2.78 and a water/cement ratio of 0.58. Control mortars and mortars with ZrO2 additions were analyzed for two stages of curing of the mortar—7 and 28 days. According to SEM analysis, mortars with ZrO2 revealed a microstructure with a high compaction degree and an increase in compressive strength of 9% on the control mortars. Due to the aggregates’ characteristics, adherence with the cement paste in the interface zone was increased. It is suggested that the reinforcing effect of ZrO2 on the mortars was caused by the effect of nucleation sites in the main phase C–S–H and the inhibition of the growth of large CH crystals, and the filler effect generated by the nanometric size of the particles. This produced a greater compaction volume, suggesting that faults are probably originated in the aggregates.

Large Size Single Crystal Growth of Ti4O7 by the Floating-Zone Method

We report the growth of large size Ti4O7 single crystals by the floating-zone method using an infrared image furnace. By employing a high rotation rate of the seed rod, we improved the temperature ...

In Situ Real-Time Annealing of Ultrathin Vertical Fe Nanowires Grown by Focused Electron Beam Induced Deposition

Focused Electron Beam Induced Deposition is a consolidated technique for the growth ofthree-dimensional (3D) nanostructures. However, this single-step nanofabricationmethod requires further efforts to optimize simultaneously dimensional andcompositional properties, in particular for deposits with a high aspect ratio. Morespecifically, ferromagnetic 3D nanowires (NWs) with diameters in the sub-50 nm regimeand high metallic contents up to 95 at. % attract great interest to improve the finalperformance of magnetic nanodevices such as magnetic tips for scanning probemicroscopy. In this work, we report on real-time monitoring during chemical purificationand structural crystallization processes of ultra-narrow 3D Fe NWs (<50 nm in diameterachieved) by post-growth in situ annealing in a transmission electron microscope. NWheating up to 700 oC in very high vacuum reveals the local increase of the metallic contentalong the entire NW length concomitant with the growth of large Fe single crystals frominitially amorphous compounds. A metallic purity of 95 at. % is observed in severalregions, dramatically boosting the initial Fe content of 40 at. %. The real-time in situtracking of 3D nanostructures during thermal annealing is a key element to design andoptimize novel purification processes for the fabrication of customized components to beintegrated in spintronic, logic and sensing devices.

An approach to high-throughput growth of submillimeter transition metal dichalcogenide single crystals.

High-throughput growth of large size transition metal dichalcogenide (TMD) single crystals is an important challenge for their applications in the next generation electronic and optoelectronic integration devices. Here we report the high-throughput growth of submillimeter monolayer TMD single crystals by two-stage space confined chemical vapor deposition, where the nucleation density of TMD crystals is significantly decreased for the growth of large size monolayer crystals by the space confinement effect. Moreover, high-throughput growth of submillimeter TMD crystals is also achieved by stacking the substrates along the perpendicular direction to the flow of the reaction gases. The mobilities of the TMD materials produced in this way are up to 1.2, 17.0 and 25.0 cm2 (V s)-1 for monolayer WS2, WSe2 and MoS2 single crystals, respectively. The results demonstrate that two-stage space confined growth is a highly promising method for high-throughput fabrication of high-quality submillimeter monolayer TMD single crystals, which will pave a new pathway to large-scale production of TMD-based electronic and optoelectronic devices.

Large bulk crystal growth by the modified infrared convergent heating floating zone method

Large bulk crystal growth by the modified infrared convergent heating floating zone method

Growth of SrTiO3 Single Crystals with a Diameter of about 30 mm by the Verneuil Method

The work demonstrates growth by the Verneuil method of SrTiO3 single crystals of 30 mm in diameter. Experiments are performed under an industrial environment. Growth was for 4.75 h, i.e., within one production shift. The optimum growth conditions for which the length of the region with bubbles D is zero and the effective length EL (i.e., the crystal length of commercial value) is maximized are for the amount of SrCO3 additive of ∼3 wt % and for H2 outer flow rate of ∼35 L/min. These two parameters show the strongest influence on the bubble-free growth, but other growth parameters (H2 inner flow rate, O2 flow rate increase, rotation speed) were also optimized. Selected crystals are characterized from the structural, microstructural, optical, and THz spectroscopy viewpoints, and they are compared with a commercial substrate and with crystals reported in the literature. This work opens the possibility for the industrial growth of large SrTiO3 single crystals and commercialization of large area substrates.

A glassy carbon electrode modified with TiO2(200)-rGO hybrid nanosheets for aptamer based impedimetric determination of the prostate specific antigen.

TiO2(200)-rGO hybrid nanosheets were synthesized starting from TiO2, rGO and NaOH solid powders via a scalable hydrothermal process. The weight ratio of TiO2-GO was found to be crucial on the crystal growth and biosensor properties of the final hybrid nanosheets. They were characterized by means of SEM, FESEM-EDX, XRD, XPS, Raman and FTIR spectroscopies in order to verify the formation of very thin TiO2 anatase nanosheets with an orientation of the anatase crystal structure towards the (200) plane. The free active sites of TiO2 structure and the large surface of the 2D graphene structure strongly facilitate charge transport confirmed by BET-BJH analyses. Compared to pure AuNPs, rGO and TiO2, the hybrid nanosheet modified electrode represents the most sensitive aptasensing platform for the determination of PSA. The detection was based on that the variation of electron transfer resistance (Rct) at the modified electrode surface in a solution containing 3.0mmolL-1 [Fe(CN)6]3-/4- as a redox probe and 0.1molL-1 KCl as supporting electrolyte. The detection limit of the sensor is 1pgmL-1, and the sensor can be operated up to 30days. It was applied to the analysis of PSA levels in spiked serum samples obtained from patients with prostate cancer. Data compare well with those obtained by an immunoradiometric assay. Graphical abstract Scalable reduced graphene oxide (rGO)-TiO2(200) mesoporous hybrid nanosheets with large surface area and new crystal growth of anatase (A) are introduced as efficient, durable, selective with low detection limit aptamer based prostate specific antigen biosensor.

Synthesis of NaxMoO3 crystals through high pressure solid-state reaction

ABSTRACTWe report growth of high-purity single crystals of the sodium molybdenum bronzes NaxMoO3 through high pressure solid-state reaction routes. Our results demonstrate that the crystallite sizes of NaxMoO3 can rapidly grow to ∼25 μm under a moderate pressure of 4.0 GPa in just 10 min. This discovery provides a starting point for the growth of large single crystals of alkali metal molybdenum bronzes under high pressure.

From Initial Hit to Crystal Optimization with Microseeding of Human Carbonic Anhydrase IX—A Case Study for Neutron Protein Crystallography

Human carbonic anhydrase IX (CA IX) is a multi-domain membrane protein that is therefore difficult to express or crystalize. To prepare crystals that are suitable for neutron studies, we are using only the catalytic domain of CA IX with six surface mutations, named surface variant (SV). The crystallization of CA IX SV, and also partly deuterated CA IX SV, was enabled by the use of microseed matrix screening (MMS). Only three drops with crystals were obtained after initial sparse matrix screening, and these were used as seeds in subsequent crystallization trials. Application of MMS, commercial screens, and refinement resulted in consistent crystallization and diffraction-quality crystals. The crystallization protocols and strategies that resulted in consistent crystallization are presented. These results demonstrate not only the use of MMS in the growth of large single crystals for neutron studies with defined conditions, but also that MMS enabled re-screening to find new conditions and consistent crystallization success.

Thermal decomposition study of nanostructured amorphous lithium, sodium and potassium metatitanates

A new method of synthesis of advanced hydrated metatitanate pseudomorphs obtained via extraction of sulfate ions from the crystals of titanyl sulfate dihydrate and their replacement with hydroxyl groups of NaOH, LiOH and KOH solutions leaving the Ti-O framework untouched has been proposed. The resulting materials exhibit specific structural properties, which were determined by a number of methods, including scanning and transmission electron microscopy, X-ray diffraction and thermal analysis coupled with mass spectrometry. It was observed that while material precipitated by KOH is thermally stable up to 150 °C, the decomposition of LiOH and NaOH materials starts right at the beginning of the heating. With the increasing temperature, the amorphous materials start to crystallize into various lithium, sodium and potassium titanates and furthermore the growth of larger crystals and nanowhiskers on rods during the crystallization process was observed and discussed.

Growth of Large Single Crystals of Copper Iodide by a Temperature Difference Method Using Feed Crystal Under Ambient Pressure

A large single crystal of CuI was fabricated by the temperature difference method using NH4I aqueous solution. To explore the efficient crystal growth condition, we calculate the phase diagram of c...

Crystallization of Methylammonium Lead Halide Perovskites by Optical Trapping.

Single crystals of organolead halide perovskites attract much attention to electrooptical and photovoltaic applications. They are usually prepared in precursor solutions incubated at controlled temperatures or under optimized vapor atmosphere conditions, and thus, multiple perovskite crystals are nucleated all over the solution. Multiple nucleation of crystals prevents efficient use of precursors in the preferential growth of large single crystals. An innovative approach is presented for spatiotemporally controlled, selective nucleation and growth of single crystals of lead halide perovskites by optical trapping with a focused laser beam. Upon such trapping in unsaturated precursor solutions, nucleation of MAPbX3 (MA=CH3 NH3 + ; X=Cl- , Br- , or I- ) is induced at the focal spot through increase in the concentration of perovskite precursors in the focal volume. The rate at which the nucleated crystal grows depends upon whether the perovskite absorbs the trapping laser or not. These findings suggest that optical trapping would be useful to prepare various perovskite single crystals and modify their optical and electronic properties; thereby, offering new methods for engineering of perovskite crystals.

Crystallization of Methylammonium Lead Halide Perovskites by Optical Trapping

AbstractSingle crystals of organolead halide perovskites attract much attention to electrooptical and photovoltaic applications. They are usually prepared in precursor solutions incubated at controlled temperatures or under optimized vapor atmosphere conditions, and thus, multiple perovskite crystals are nucleated all over the solution. Multiple nucleation of crystals prevents efficient use of precursors in the preferential growth of large single crystals. An innovative approach is presented for spatiotemporally controlled, selective nucleation and growth of single crystals of lead halide perovskites by optical trapping with a focused laser beam. Upon such trapping in unsaturated precursor solutions, nucleation of MAPbX3 (MA=CH3NH3+; X=Cl−, Br−, or I−) is induced at the focal spot through increase in the concentration of perovskite precursors in the focal volume. The rate at which the nucleated crystal grows depends upon whether the perovskite absorbs the trapping laser or not. These findings suggest that optical trapping would be useful to prepare various perovskite single crystals and modify their optical and electronic properties; thereby, offering new methods for engineering of perovskite crystals.