Temperature dependent crystallization of Cu2O rhombic dodecahedra

CrystEngComm ◽  
2021 ◽  
Author(s):  
Zhiqiang Wang ◽  
Wangzhu Cao ◽  
Kunfeng Chen ◽  
Dongfeng Xue
Keyword(s):  
Crystallization Process ◽  
Synthesis Condition ◽  
Temperature Dependent ◽  
Size And Shape ◽  
Rhombic Dodecahedra

Size and shape uniformity of nanomaterials are extremely important for their applications in batteries, supercapacitors, catalysis, etc. In the crystallization process, finding proper synthesis condition is necessary to control over...

Effects of Impurities on the Competition between Solid Phase Epitaxy and Random Crystallization In Ion-Implanted Silicon

1984 ◽  
Vol 35 ◽  
Author(s):  
G.L. Olson ◽  
J.A. Roth ◽  
Y. Rytz-Froidevaux ◽  
J. Narayan
Keyword(s):  
Laser Heating ◽  
Crystallization Process ◽  
Solid Phase ◽  
Crystallization Rate ◽  
Solid Phase Epitaxy ◽  
Temperature Dependent ◽  
Kinetics Parameters ◽  
Time Resolved ◽  
Cw Laser ◽  
Ion Implanted

ABSTRACTThe temperature dependent competition between solid phase epitaxy and random crystallization in ion-implanted (As+, B+, F+, and BF2+) silicon films is investigated. Measurements of time-resolved reflectivity during cw laser heating show that in the As+, F+, and BF2+-implanted layers (conc 4×1020cm-3) epitaxial growth is disrupted at temperatures 1000°C. This effect is not observed in intrinsic films or in the B+-implanted layers. Correlation with results of microstructural analyses and computer simulation of the reflectivity experiment indicates that disruption of epitaxy is caused by enhancement of the random crystallization rate by arsenic and fluorine. Kinetics parameters for the enhanced crystallization process are determined; results are interpreted in terms of impurity-catalyzed nucleation during the random crystallization process.

Solubility of Carbamazepine-Succinic Co-Crystal in Ethanolic Solvent System

2015 ◽  
Vol 1113 ◽  
pp. 434-439
Author(s):  
Noor Ashila Ramle ◽  
Syarifah Abd Rahim ◽  
Omar El-Hadad ◽  
Nornizar Anuar
Keyword(s):  
Succinic Acid ◽  
Crystallization Process ◽  
Solvent System ◽  
Dissolution Process ◽  
Second Law ◽  
Temperature Dependent ◽  
Ethanolic Solution ◽  
Solution System ◽  
Different Temperatures ◽  
Solvent Systems

Solubility of carbamazepine co-crystal produced from cooling co-crystallization process with succinic acid as a co-crystal former is investigated in this study. Two techniques were used to determine the solubility of the co-crystal which are gravimetry and HPLC. The solubility experiments in ethanol solvent systems were conducted at 6 different temperatures (25, 30, 35, 40, 45 and 50 °C) while for succinic acid ethanolic solution system were conducted at 5 different concentration ratios. Both of the systems are equilibrated for 72 hours. Result from the experiments has shown that the solubility of co-crystal is temperature dependent. As the temperature increases, the solubility of co-crystal also increases; this agrees with the Second Law of Thermodynamic which states that heat facilitates the dissolution process by providing more energy to the system.

scholarly journals Size- and shape-controlled synthesis of Prussian Blue nanoparticles by a polyvinylpyrrolidone-assisted crystallization process

CrystEngComm ◽  
2012 ◽  
Vol 14 (10) ◽  
pp. 3387 ◽  
Author(s):  
Hu Ming ◽  
Nagy L. K. Torad ◽  
Ya-Dong Chiang ◽  
Kevin C.-W. Wu ◽  
Yusuke Yamauchi
Keyword(s):  
Prussian Blue ◽  
Crystallization Process ◽  
Controlled Synthesis ◽  
Size And Shape ◽  
Prussian Blue Nanoparticles ◽  
Shape Controlled

Orthogonal Smectic Layers Favour Nucleation through Diffusioncontrolled Transformations: A Systematic Crystallization Kinetics Study

2002 ◽  
Vol 57 (5) ◽  
pp. 226-232 ◽  
Author(s):  
P. A. Kumar ◽  
Pisupati Swathi ◽  
V. G. K. M. Pisipati
Keyword(s):  
Differential Scanning Calorimetry ◽  
Crystal Growth ◽  
Crystallization Kinetics ◽  
Crystallization Process ◽  
Avrami Exponent ◽  
Kinetics Study ◽  
Nucleation Process ◽  
Temperature Dependent ◽  
Scanning Calorimetry ◽  
Kinetics Of

Systematic investigations of the crystallization kinetics of two representative compounds of p-phenylbenzylidene-p´ -alkylanilines are performed, using differential scanning calorimetry, to study the influence of the kinetophase (occurs prior to the crystal phase) on the nucleation process. The dimensionality of the crystal growth and the related crystallization process are discussed in terms of the Avrami parameters n and b. The trend in the magnitude of the Avrami exponent n supports the occurrence of temperature-dependent transformations in the orthorhombic molecular array.

Temperature Dependent Tissue Properties and Ultrasonic Lesion Formation

1999 ◽  
Author(s):  
Michael C. Kolios ◽  
Michael D. Sherar ◽  
John W. Hunt
Keyword(s):  
Theoretical Model ◽  
High Intensity ◽  
Focused Ultrasound ◽  
High Intensity Focused Ultrasound ◽  
Bioheat Transfer ◽  
Tissue Temperature ◽  
Focal Region ◽  
Temperature Dependent ◽  
Size And Shape ◽  
Temperature Distributions

Abstract High intensity focused ultrasound has considerable potential for the noninvasive treatment of localised disease. A detailed understanding of the kinetics of tissue coagulation is required to optimise ultrasonic parameters. In this presentation a theoretical model was used to examine the effects of temperature dependent ultrasonic attenuation and absorption on the transient tissue temperature distributions and lesion dimensions. A finite difference algorithm was used to solve numerically the nonlinear form of the bioheat transfer equation in cylindrical coordinates. The lesion dimensions were calculated based on the time-temperature distributions in tissue by using a thermal dose threshold to define the lesion boundaries. The results were compared to published experimental data in which the the location of maximal energy deposition during short duration high intensity focused ultrasound irradiation of in vitro tissue was examined. It was found that the theoretical model did not predict the size and shape of the experimental lesions. To correctly predict lesion size and shape much higher values of attenuation and absorption were required than can be accounted for by thermal coagulation of the tissue alone. The values used suggest that for intensities greater than 3030 W/cm2 the effective local attenuation/absorption in the focal region increased by a factor of 10–20. It is finally shown that temperature dependent tissue changes should be incorporated in thermal models to avoid underestimation of the induced temperature distributions during high intensity focused ultrasound therapy.

Amorphous-to-polycrystalline phase transformations in Sn-implanted silicon

1990 ◽  
Vol 5 (5) ◽  
pp. 1003-1012 ◽  
Author(s):  
R.P. Thornton ◽  
R.G. Elliman ◽  
J.S. Williams
Keyword(s):  
Activation Energy ◽  
Phase Transformation ◽  
Crystallization Process ◽  
Large Fraction ◽  
Temperature Dependent ◽  
Near Surface ◽  
Fine Grain ◽  
Polycrystalline Phase ◽  
Amorphous Si ◽  
Time Required

An amorphous-to-fine-grain-polycrystalline phase transformation has been observed during annealing of Sn-implanted Si when the peak Sn concentration exceeds about 2 at.%. At lower Sn concentrations, epitaxial growth is retarded in (100) Si but proceeds to completion with a large fraction of Sn residing on substitutional lattice sites. As the Sn concentration is increased, epitaxy is pre-empted by the sudden transformation of the near-surface Sn-doped region into polycrystalline Si. The time required to initiate the transformation is temperature dependent and is characterized by an activation energy of ∼1.7 eV. Rapid redistribution of Sn has been observed to accompany the transformation. Our observations are shown to be consistent with a melt-mediated crystallization process which is rate limited by Sn diffusion and precipitation in amorphous Si.

Unbiased estimation of particle number and sizes using the new stereological tools: the disector, the fractionator, the selector, and the nucleator — or just point-sampled intercepts

1988 ◽  
Vol 46 ◽  
pp. 428-429
Author(s):  
H.J.G. Gundersen
Keyword(s):  
Particle Number ◽  
Small Distance ◽  
Parallel Plane ◽  
Unbiased Estimation ◽  
Severe Problem ◽  
New Era ◽  
Size And Shape ◽  
Distinct Property ◽  
Sectioned Tissue

Previously, all stereological estimation of particle number and sizes were based on models and notoriously gave biased results, were very inefficient to use and difficult to justify. For all references to old methods and a direct comparison with unbiased methods see recent reviews.The publication in 1984 of the DISECTOR, the first unbiased stereological probe for sampling and counting 3—D objects irrespective of their size and shape, signalled the new era in stereology — and give rise to a number of remarkably simple and efficient techniques based on its distinct property: It is the only known way to obtain an unbiased sample of 3-D objects (cells, organelles, etc). The principle is simple: within a 2-D unbiased frame count or sample only cells which are not hit by a parallel plane at a known, small distance h.The area of the frame and h must be known, which might sometimes in itself be a problem, albeit usually a small one. A more severe problem may arise because these constants are known at the scale of the fixed, embedded and sectioned tissue which is often shrunken considerably.

(111) Monocrystalline Nickel Films

1972 ◽  
Vol 30 ◽  
pp. 512-513
Author(s):  
T.E. Pratt ◽  
R.W. Vook
Keyword(s):  
Film Thickness ◽  
Deposition Rate ◽  
Room Temperature ◽  
Narrow Range ◽  
High Vacuum ◽  
Residual Pressure ◽  
Temperature Dependent ◽  
Deposition Parameters ◽  
Transmission Electron ◽  
Substrate Temperatures

(111) oriented thin monocrystalline Ni films have been prepared by vacuum evaporation and examined by transmission electron microscopy and electron diffraction. In high vacuum, at room temperature, a layer of NaCl was first evaporated onto a freshly air-cleaved muscovite substrate clamped to a copper block with attached heater and thermocouple. Then, at various substrate temperatures, with other parameters held within a narrow range, Ni was evaporated from a tungsten filament. It had been shown previously that similar procedures would yield monocrystalline films of CU, Ag, and Au.For the films examined with respect to temperature dependent effects, typical deposition parameters were: Ni film thickness, 500-800 A; Ni deposition rate, 10 A/sec.; residual pressure, 10-6 torr; NaCl film thickness, 250 A; and NaCl deposition rate, 10 A/sec. Some additional evaporations involved higher deposition rates and lower film thicknesses.Monocrystalline films were obtained with substrate temperatures above 500° C. Below 450° C, the films were polycrystalline with a strong (111) preferred orientation.

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