Crystal Growth Data Research Articles

Complex Growth of Benzamide Form I: Effect of Additives, Solution Flow, and Surface Rugosity.

Understanding crystal growth kinetics is of great importance for the development and manufacturing of crystalline molecular materials. In this work, the impact of additives on the growth kinetics of benzamide form I (BZM-I) crystals has been studied. Using our newly developed crystal growth setup for the measurement of facet-specific crystal growth rates under flow, BZM-I growth rates were measured in the presence of various additives previously reported to induce morphological changes. The additives did not have a significant impact on the growth rates of BZM-I at low concentrations. By comparison to other systems, these additives could not be described as “effective” since BZM-I showed a high tolerance of the additives’ presence during growth, which may be a consequence of the type of growth mechanisms at play. Growth of pure BZM-I was found to be extremely defected, and perhaps those defects allow the accommodation of impurities. An alternative explanation is that at low additive concentrations, solid solutions are formed, which was indeed confirmed for a few of the additives. Additionally, the growth of BZM-I was found to be significantly affected by solution dynamics. Changes in some facet growth rates were observed with changes in the orientation of the BZM-I single crystals relative to the solution flow. Of the two sets of facets involved in the growth of the width and length of the crystal, the {10l̅} facets were found to be greatly affected by the solution flow while the {011} facets were not affected at all. Computational fluid dynamics simulations showed that solute concentration has higher gradients at the edges of the leading edge {10l̅} facets, which can explain the appearance of satellite crystals. {10l̅} facets were found to show significant structural rugosity at the molecular level, which may play a role in their mechanism of growth. The work highlights the complexities of measuring crystal growth data of even simple systems such as BZM-I, specifically addressing the effect of additives and fluid dynamics.

Decelerated crystal growth in a soda-lime-silica glass

Isolated Na2O⋅2CaO⋅3SiO2 (NC2S3) single crystals grew at temperatures above glass transition in a melt with a slight soda excess. The enrichment of Na in the continuous solid solution Na4+2zCa4–z[Si6O18] (with 0 ≤ z ≤ 1) upon crystallisation causes a depletion of soda of the growing interfacial diffusion zone. Therefore its viscosity will change. Experimental data and idealized model calculations of the viscosity show the same trend and indicate that the viscosity of the interfacial zone would be up to several orders of magnitude higher than the viscosity of the melt. This increased viscosity at the crystal growth front and the experimentally observed decrease of the crystallisation velocity with crystal size suggest a linear increase of the effective activation enthalpy of the diffusional transport through the diffusion zone with crystal size, which allows to quantitatively model crystal growth data of the NC2S3 glass investigated.

Real-time prediction of interstitial oxygen concentration in Czochralski silicon using machine learning

We developed a machine learning model to predict interstitial oxygen (Oi) concentration in a Czochralski-grown silicon crystal. A highly accurate prediction can be ensured by selecting the appropriate experimental parameters that represent the change in the furnace conditions. A neural network was trained using the dataset of 450 ingots, and its prediction error for the testing dataset was 4.2 × 1016 atoms cm−3. Finally, a real-time prediction system was developed wherein the crystal growth data are input into the model, and the Oi concentration at the current growth interface is calculated immediately.

Comments on “Investigation on novel bulk size single crystal of Glycine with metal ions grown by solution growth method for photonic applications”

The authors of the title paper (Materials Letters 257 (2019) 126674) report to have grown a glycine potassium dichromate (GPDC) single crystal by slow evaporation of an aqueous solution containing equimolar quantities of glycine and potassium dichromate. In this comment, many points of criticism, concerning the crystal growth and experimental data for this so-called GPDC crystal are discussed to prove that it is a dubious material.

Crystal growth kinetics of unseeded high silica chabazite

Crystal growth of high silica chabazite using N,N,N-1-adamantammoniumhydroxide (TMAdaOH) as structure directing agent (SDA) were studied at 140–170 °C between 24 and 168 h using a direct method. Crystal growth rate increased when the temperature increased. The systems linear crystal growth rates were constant between 24 and 72 h at 150–160 °C. This allowed crystal growth data to be fitted with an empirical method for solid state kinetic processes and subsequent calculation of the systems apparent crystal growth activation energy. The magnitude of the activation energy indicates that the systems crystal growth is controlled by surface kinetics. At 170 °C the zeolite system displayed a non-constant linear crystal growth rate. The linear non-constant growth rate was attributed to surface processes resulting in transformation of spherical to cubic crystals as observed with scanning electron microscopy.

Crystal-growth kinetics of magnetite (Fe3O4) nanoparticles with Ostwald Ripening Model approach

Magnetite (Fe3O4) nanoparticles is a magnetic nanomaterial that have potential properties to be applied as drug delivery The purpose of this study was to determine the influence of time and temperature synthesis of magnetie characteristics and determine its crystal growth kinetics model with Ostwald ripening model approach. Magnetite nanoparticles synthesized from FeCl3, citrate, urea and polyethylene glycol with hydrothermal method at 180, 200 and 220 °C for 1,3,5,7,9 and 12 hours. Characterization by X-ray Diffraction (XRD) indicated that magnetite formed at temperatures of 200 and 220 °C. Magnetite crystallite diameter obtained was 10-29 nm. Characterization by Transmission Electron Mycroscope (TEM) shows that magnetite nanoparticles have uniform size and non-agglomerated. Core-shell shaped particles formed at 200 °C and 220 °C for 3 hours. Irregular shape obtained at 220 °C for 12 hour synthesis with particle diameter about 120 nm. Characterization using Vibrating Sample Magnetometer (VSM) shown that magnetite has super paramagnetism behaviour with the highest saturation magnetization (Ms) was 70.27 emu/g. magnetite crystal growth data at temperature of 220 °C can be fitted by Ostwald ripening growth model with growth controlled by the dissolution of surface reaction (n≈4) with the percent error of 2.53%.

Preliminary neutron diffraction analysis of challenging human manganese superoxide dismutase crystals.

Superoxide dismutases (SODs) are enzymes that protect against oxidative stress by dismutation of superoxide into oxygen and hydrogen peroxide through cyclic reduction and oxidation of the active-site metal. The complete enzymatic mechanisms of SODs are unknown since data on the positions of hydrogen are limited. Here, methods are presented for large crystal growth and neutron data collection of human manganese SOD (MnSOD) using perdeuteration and the MaNDi beamline at Oak Ridge National Laboratory. The crystal from which the human MnSOD data set was obtained is the crystal with the largest unit-cell edge (240 Å) from which data have been collected via neutron diffraction to sufficient resolution (2.30 Å) where hydrogen positions can be observed.

Crystal growth in Se70Te30 thin films followed by SEM and in situ XRD

The isothermal crystal growth kinetics in Se70Te30 thin films was investigated using the microscopy and in situ X-ray diffraction (XRD) measurements. Plate-like crystals grew linearly with time which is the sign of liquid-crystal interface kinetics. In the studied temperature range, from 68 °C to 88 °C, crystal growth rates exhibit simple exponential behavior with an activation energy of crystal growth EG = 168 ± 12 kJ mol−1. The growth data obtained from the microscopy measurements were combined with viscosity data, melting parameters and the appropriate crystal growth model was assessed. The relation between the kinetic coefficient of crystal growth and viscosity (u∝η-ξ) is described in detail, and a correction of the standard growth model is suggested. The crystal growth data obtained from the in situ XRD measurements were described using the Johnson-Mehl-Avrami nucleation-growth model with the Avrami exponent m = 2.2 ± 0.2. The activation energy of the overall crystallization process EA was estimated and its value is 171 ± 11 kJ mol−1.

Crystallization of Itraconazole Polymorphs from Melt

The impacts of the nucleation site and temperature on the melt crystallization of itraconazole (ITZ) were investigated. ITZ recrystallized from melt into three distinct spherulite zones between two glass coverslips, as observed under a polarized light microscope. The first two corresponded to Forms I and II which are monotropically related, as determined by solubility and thermal analyses. The third zone differed from the other two in the X-ray powder diffraction pattern, thermal properties, Fourier transform infrared spectrum, and dissolution rate, indicative of a new form (III) which has not been reported previously. Form III readily converted to the more stable Form II with the evolution of heat upon heating above 100 °C or Form I upon dissolution in aqueous ethanol. At 70–150 °C, Form II exhibited the fastest bulk crystal growth, followed successively by Form I and Form III. Analysis of the crystal growth data using the two-dimensional nucleation model afforded good data fitting with the model and rev...

High-density grids for efficient data collection from multiple crystals.

Higher throughput methods to mount and collect data from multiple small and radiation-sensitive crystals are important to support challenging structural investigations using microfocus synchrotron beamlines. Furthermore, efficient sample-delivery methods are essential to carry out productive femtosecond crystallography experiments at X-ray free-electron laser (XFEL) sources such as the Linac Coherent Light Source (LCLS). To address these needs, a high-density sample grid useful as a scaffold for both crystal growth and diffraction data collection has been developed and utilized for efficient goniometer-based sample delivery at synchrotron and XFEL sources. A single grid contains 75 mounting ports and fits inside an SSRL cassette or uni-puck storage container. The use of grids with an SSRL cassette expands the cassette capacity up to 7200 samples. Grids may also be covered with a polymer film or sleeve for efficient room-temperature data collection from multiple samples. New automated routines have been incorporated into the Blu-Ice/DCSS experimental control system to support grids, including semi-automated grid alignment, fully automated positioning of grid ports, rastering and automated data collection. Specialized tools have been developed to support crystallization experiments on grids, including a universal adaptor, which allows grids to be filled by commercial liquid-handling robots, as well as incubation chambers, which support vapor-diffusion and lipidic cubic phase crystallization experiments. Experiments in which crystals were loaded into grids or grown on grids using liquid-handling robots and incubation chambers are described. Crystals were screened at LCLS-XPP and SSRL BL12-2 at room temperature and cryogenic temperatures.

In vitro calcite crystal morphology is modulated by otoconial proteins otolin-1 and otoconin-90.

Otoconia are formed embryonically and are instrumental in detecting linear acceleration and gravity. Degeneration and fragmentation of otoconia in elderly patients leads to imbalance resulting in higher frequency of falls that are positively correlated with the incidence of bone fractures and death. In this work we investigate the roles otoconial proteins Otolin-1 and Otoconin 90 (OC90) perform in the formation of otoconia. We demonstrate by rotary shadowing and atomic force microscopy (AFM) experiments that Otolin-1 forms homomeric protein complexes and self-assembled networks supporting the hypothesis that Otolin-1 serves as a scaffold protein of otoconia. Our calcium carbonate crystal growth data demonstrate that Otolin-1 and OC90 modulate in vitro calcite crystal morphology but neither protein is sufficient to produce the shape of otoconia. Coadministration of these proteins produces synergistic effects on crystal morphology that contribute to morphology resembling otoconia.

Growth of Devitrite, Na2Ca3Si6O16, in Soda–Lime–Silica Glass

The morphology and crystal growth of devitrite crystals nucleated heterogeneously on glass surfaces have been studied. The crystals grow as fans of needles, with each needle having a characteristic [100] growth direction with respect to the centrosymmetric triclinic unit cell. An analysis of crystal growth data reported here and a reappraisal of crystal growth data reported in prior studies suggests a best estimate of 260 kJ/mol for the activation enthalpy for the crystal growth of devitrite along [100], higher than the values previously reported.

Crystallization from Solutions Containing Multiple Conformers. 2. Experimental Study and Model Validation

In this Article, the validity of a model derived for crystal growth rates and supersaturation for solids crystallized from solutions of materials containing multiple conformers is evaluated. A simple and straightforward method for determining crystal growth rates using FBRM and FTIR/ATR is utilized, which leads to a large amount of growth rate data from a single experiment. Supersaturation and crystal growth rate obtained experimentally were in good agreement with model predictions. In particular, data indicated that for the system at hand, crystal growth rate is inversely proportional to crystals size. Further, the solute integration coefficient determined from supersaturation measurements can be slightly overestimated due to surface nucleation and/or agglomeration that can result from supersaturation spikes during antisolvent addition. Last, crystal growth data obtained at different temperatures indicated that slow growth rate observed at low temperatures is likely to be due in part to surface poisoning...

Fabrication of X-ray compatible microfluidic platforms for protein crystallization.

This paper reports a method for fabricating multilayer microfluidic protein crystallization platforms using different materials to achieve X-ray transparency and compatibility with crystallization reagents. To validate this approach, three soluble proteins, lysozyme, thaumatin, and ribonuclease A were crystallized on-chip, followed by on-chip diffraction data collection. We also report a chip with an array of wells for screening different conditions that consume a minimal amount of protein solution as compared to traditional screening methods. A large number of high quality isomorphous protein crystals can be grown in the wells, after which slices of X-ray data can be collected from many crystals still residing within the wells. Complete protein structures can be obtained by merging these slices of data followed by further processing with crystallography software. This approach of using an x-ray transparent chip for screening, crystal growth, and X-ray data collection enables room temperature data collection from many crystals mounted in parallel, which thus eliminates crystal handling and minimizes radiation damage to the crystals.

Determination of crystal growth rate for porcine insulin crystallization with CO2 as a volatile acidifying agent

Crystallization is controlled by two steps that determine the quality and the final size of the product, nucleation and growth, which are functions of supersaturation. Recently, Hirata et al. [1] crystallized insulin using CO2 as a volatile acid to impose supersaturation on the system. The objective of the present work was to determine the growth kinetics of insulin crystallization in 50mM NaHCO3 solution with 0.4mM ZnCl2 in a CO2 atmosphere at 15°C, adjusting the parameters of the equation G=kg×Sg to the experimental data. The solubility of insulin in the NaHCO3/CO2/ZnCl2 system at 15°C was determined as a function of pH in the range of 6.30–7.34. The crystal growth data allowed determination of the growth order “g” (g=2.9). Although protein crystallization has some features that differ from the crystallization of less complex molecules, the apparent growth kinetics of insulin were successfully analyzed here with the same empirical methods used for small molecules, which can easily be scaled up for industrial applications to achieve specific size and purity, the goals of industrial crystallization. The method used in this work is a useful tool for describing and simplifying optimization of industrial protein crystallization processes.

Crystal Growth and Powder X-Ray Diffraction Data of Cadmium Zinc Tellurium (Cd0.29Zn0.71Te)

X-ray powder diffraction data for a new Cadmium Zinc Tellurium compound synthesized by Bridgman technique is reported. The unit cell dimensions were determined from diffractometer methods using CuK radiation, and the indexing programs. The cubic phase was the sole crystalline phase which detected by X-ray diffraction analysis in the Cd0.29Zn0.71Te sample with lattice constants of a= 6.26218(34) A, The results are in agreement with those obtained from cadmium Zinc tellurium (Cd0.4Zn0.6Te) PDF carte number (50-1438).

Identification of geometrical models of interface evolution for dendritic crystal growth

This Letter introduces a method for identifying geometrical models of interface evolution, directly from experimental imaging data. These local growth models relate normal growth velocity to curvature and its derivatives estimated along the growing interface. Such models can reproduce many qualitative features of dendritic crystal growth as well as predict quantitatively its early stages of evolution. Numerical simulations and experimental crystal growth data are used to demonstrate the applicability of this approach.

Method for the prediction of nuclear waste solution decontamination by coprecipitation of strontium ions with barium sulphate using the experimental data obtained in non-radioactive environment

The theoretical and experimental prediction of the decontamination factor during the treatment of nuclear waste solutions is generally a cumbersome problem due to their complex composition and extremely dangerous environment. Here, a methodology is proposed and experimentally validated allowing the prediction of the decontamination factor by carrying out experiments in small pilot installations in non-radioactive environment. These experiments provide the population density and the crystal growth data of the coprecipitating agent which serve for calculations according to the general relation presented in this paper.

A Kinetic Model To Simulate Protein Crystal Growth in an Evaporation-Based Crystallization Platform

The quality, size, and number of protein crystals grown under conditions of continuous solvent extraction are dependent on the rate of solvent extraction and the initial protein and salt concentration. An increase in the rate of solvent extraction leads to a larger number of crystals. The number of crystals decreases, however, when the experiment is started with an initial protein concentration that is closer to the solubility boundary. Here we develop a kinetic model capable of predicting changes in the number and size of protein crystals as a function of time under continuous evaporation. Moreover, this model successfully predicts the initial condition of drops that will result in gel formation. We test this model with experimental crystal growth data of hen egg white lysozyme for which crystal nucleation and growth rate parameters are known from other studies. The predicted and observed rates of crystal growth are in excellent agreement, which suggests that kinetic constants for nucleation and crystal growth for different proteins can be extracted by applying a kinetic model in combination with observations from a few evaporation-based crystallization experiments.

Nucleation and crystal growth of zirconium molybdate hydrate in nitric acid

Zirconium molybdate hydrate can precipitate in nitric acid media during the process of spent nuclear fuel recycling. The precipitates can occur either in the nitric acid dissolution solution or in the waste fission product solution, and can lead to the formation of fouling layers. If such layers are left to grow, they can generate dysfunctions requiring heavy mechanical intervention and lead to production losses. In order to reduce the fouling risk as much as possible, nucleation and crystal growth data of zirconium molybdate hydrate in nitric acid are used to propose a fouling mechanism. Two parameters, supersaturation ratio and temperature, are used with the classical theory of primary nucleation to describe the stability of the supersaturated solutions within an observation time scale of approximately one hour. A quartz crystal microbalance is used to measure zirconium molybdate hydrate crystal growth kinetics on an initial crystal deposit. The collected data allocated four zones delimited by supersaturation ratios and temperatures, each zone describing a specific behaviour of zirconium and molybdenum solutions in nitric acid. As a result, a fouling scenario is proposed and the data is used to greatly limit its growth.