Влияние температуры отжига на кинетику процесса алюминий-индуцированной кристаллизации тонких пленок аморфного субоксида кремния

2021 ◽  
Vol 47 (21) ◽  
pp. 39
Author(s):  
И.Е. Меркулова ◽  
А.О. Замчий ◽  
Н.А. Лунев ◽  
В.О. Константинов ◽  
Е.А. Баранов -=SUP=-1-=/SUP=-
Keyword(s):  
Annealing Temperature ◽  
Silicon Oxide ◽  
Arrhenius Plot ◽  
Nucleation Density ◽  
Diffusion Limited Aggregation ◽  
Annealing Temperatures ◽  
Diffusion Limited ◽  
First Time ◽  
Kinetics Of ◽  
Induced Crystallization

In this work, the kinetics of aluminum-induced crystallization (AIC) of non-stoichiometric silicon oxide a-SiO0.25 was investigated for annealing temperatures of 370, 385 and 400 °C, as a result of which thin films of polycrystalline silicon were obtained. It is shown that for low annealing temperatures, the surface morphology of the crystalline material is represented by dendric structures corresponding to the growth model with diffusion-limited aggregation. In addition, with an increase in the annealing temperature, the nucleation density increases from 3 to 53 mm–2. From the Arrhenius plot, the activation energy of the AIC process of a-SiO0.25 was obtained for the first time, which was 3.7±0.4 eV.

A New Field-Aided Germanium-Induced Lateral Crystallization of Silicon

2001 ◽  
Vol 664 ◽  
Author(s):  
Kianoush Naeli ◽  
Shamsoddin Mohajerzadeh ◽  
Ali Khakifirooz ◽  
Saber Haji ◽  
Ebrahim A. Soleimani
Keyword(s):  
Electric Field ◽  
Grain Growth ◽  
Negative Electrode ◽  
Crystallization Rate ◽  
Lateral Growth ◽  
Annealing Temperatures ◽  
Lateral Crystallization ◽  
Si Films ◽  
First Time ◽  
Induced Crystallization

ABSTRACTThe effect of an electric field on germanium-seeded lateral crystallization of a-Si is studied for the first time and compared to this effect in Ni-induced lateral growth. While the crystallization rate is lower when Ge is used as the nucleation seed and annealing should be done at higher temperatures, filed-aided crystallization shows a similar behavior to that observed for Ni-induced crystallization. Optical microscopy results indicate that grain growth starting from the negative electrode occurs in Si films at annealing temperatures higher than 480°C, while the applied electric field ranges form 200 to 1400V/cm. SEM was also used to confirm the crystallinity of the films.

scholarly journals Investigation into mechanisms and kinetics of asphaltene aggregation in toluene/n-hexane mixtures

2019 ◽  
Vol 17 (2) ◽  
pp. 457-466
Author(s):  
Bahram Soltani Soulgani ◽  
Fatemeh Reisi ◽  
Fatemeh Norouzi
Keyword(s):  
Image Processing ◽  
Fractal Theory ◽  
Particle Growth ◽  
Force Balance ◽  
Asphaltene Precipitation ◽  
Diffusion Limited Aggregation ◽  
Model Calculations ◽  
Diffusion Limited ◽  
Kinetics Of ◽  
And Diffusion

Abstract Determining the rate of asphaltene particle growth is one of the main problems in modeling of asphaltene precipitation and deposition. In this paper, the kinetics of asphaltene aggregation under different precipitant concentrations have been studied. The image processing method was performed on the digital photographs that were taken by a microscope as a function of time to determine the asphaltene aggregation growth mechanisms. The results of image processing by MATLAB software revealed that the growth of asphaltene aggregates is strongly a function of time. Different regions could be recognized during asphaltene particle growth including reaction- and diffusion-limited aggregation followed by reaching the maximum asphaltene aggregate size and start of asphaltene settling and the final equilibrium. Modeling has been carried out to predict the growth of asphaltene particle size based on the fractal theory. General equations have been developed for kinetics of asphaltene aggregation for reaction-limited aggregation and diffusion-limited aggregation. The maximum size of asphaltene aggregates and settling time were modeled by using force balance, acting on asphaltene particles. Results of modeling show a good agreement between laboratory measurements and model calculations.

A Study of Loop Evolution During Inert Ambient Annealing and Reaction Between Point Defects and Dislocation Loops During Oxidation of Silicon

1994 ◽  
Vol 354 ◽  
Author(s):  
J. Liu ◽  
K. S. Jones
Keyword(s):  
Point Defects ◽  
Annealing Temperature ◽  
Arrhenius Plot ◽  
Type Ii ◽  
Dislocation Loops ◽  
Plan View ◽  
Annealing Behavior ◽  
Diffusion Limited ◽  
Rate Versus ◽  
Range Type

AbstractIn the first part of this work, a plan-view TEM study has been made of the time-dependent annealing behavior of end of range (type II) dislocation loops introduced by lxl015/cm2 50KeV Si+ implantation into silicon. The activation energy for loop growth was determined to be 1.0±0.2eV from the Arrhenius plot of loop growth rate versus the reciprocal of annealing temperature. In the second part of this study, a thin boron layer was used as a diffusion monitor. The number of injected interstitials as a result of oxidation was measured by TEM. The diffusivity of boron with and without the presence of loops was studied by fitting experimental SIMS profiles with FLOOPS simulations. The interaction between loops and interstitials was determined to be diffusion limited.

Diffusion-Governed-Asymmetric Growth of Amorphous Layer Under Solid-State Reaction in Ni-Zr Multilayers

1997 ◽  
Vol 481 ◽  
Author(s):  
B. X. Liu ◽  
W. S. Lai
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Amorphous Layer ◽  
Dynamics Simulation ◽  
Atomic Process ◽  
Diffusion Limited ◽  
Asymmetric Growth ◽  
Body Potential ◽  
First Time ◽  
Kinetics Of

ABSTRACTA molecular-dynamics simulation with an n-body potential was performed to study solid-state amorphization in the Ni-Zr system upon annealing at medium temperatures ranging from 300 to 600 °C. The models for simulation were a Zr-Ni-Zr sandwich consisting of both hcp Zr and fcc Ni (001) atomic planes and a bilayer with a thin preset disordered interfacial layer, respectively, for revealing the detailed amorphization process and the growing kinetics of an amorphous layer upon solid-state reaction. Our simulation results demonstrated, for the first time, that the atomic process proceeded through first diffusion, then alloying and eventually amorphization. In other words, amorphization was controlled by a diffusion-limited reaction and the growth kinetics of the amorphous layer followed exactly a t1/2 law. Another interesting finding was that the growing speeds of the amorphous layer exhibited an asymmetric behavior, i.e. the amorphous layer extended faster towards Ni lattice than that directed to Zr side. Besides, it was also found that an initiation of amorphization upon annealing was dependent to the interfacial textures, i.e. amorphization could take place when the interfaces were composed of the more open atomic planes, whereas it was suppressed if the interfaces were constructed with the close-packed planes of both lattices.

scholarly journals Cellular Automata Modeling of Silica Aerogel Condensation Kinetics

Gels ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 50
Author(s):  
Nina H. Borzęcka ◽  
Bartosz Nowak ◽  
Rafał Pakuła ◽  
Robert Przewodzki ◽  
Jakub M. Gac
Keyword(s):  
Condensation Reaction ◽  
Gelation Time ◽  
Aggregate Size ◽  
Collision Probability ◽  
Model Parameters ◽  
Gel Properties ◽  
Diffusion Limited Aggregation ◽  
Diffusion Limited ◽  
Kinetics Of ◽  
Simulation Time

The formation of silica aerogels and the kinetics of condensation were investigated numerically. The influence of the reaction-limited to the diffusion-limited aggregation (RLA to DLA) transition on the reaction kinetics curves and the evolution of the aggregate size distribution during condensation were examined. The 2D cellular automaton was developed and applied to reflect the process of secondary particle aggregation. Several tendencies were observed due to the adjustment of the model parameters: the probability of condensation reaction and the particles’ concentration. The final wet-gel structures’ visualizations proves that the structure becomes more dense and compact due to entering the RLA regime. The simulation time (associated with the gelation time) decreased along with the increase in both model parameters. The lower the collision probability, the slower reaction becomes, and particles are more likely to penetrate the structure deeper until they finally join the aggregate. The developed model reflects the condensation process’s nature and its mechanisms properly and indicates a significant potential for further aerogel synthesis investigations and for the prediction of wet-gel properties according to condensation parameters.

Zeolites Fit For A Crown: Probing Host-Guest Interactions with Thermogravimetric Methods

2018 ◽  
Author(s):  
Asel Sartbaeva ◽  
Paul R. Raithby ◽  
Remi Castaing ◽  
Antony Nearchou
Keyword(s):  
Mass Spectrometry ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Petrochemical Industry ◽  
Rational Use ◽  
New Methodologies ◽  
First Time ◽  
Kinetics Of

Through a combination of thermogravimetry, mass spectrometry and differential thermal analysis, we demonstrate for the first time that all four zeolites show experimental differences in their host-guest interactions with 18C6. In addition, we have estimated the kinetics of 18C6 decomposition, which is a technique that has not been applied to zeolites previously. Using these findings as a toolkit, a more rational use of OSDAs can be utilised to prepare designer zeolites. Furthermore, the new methodologies presented herein can be applied to current zeolites, such as MFI-type zeolites used in the petrochemical industry.

Improvement of the Specific Contact Resistance on P-Type 4H-SiC by Using a Highly P-Typed Doped 4H-SiC Layer Selectively Grown by VLS Transport

2014 ◽  
Vol 806 ◽  
pp. 57-60
Author(s):  
Nicolas Thierry-Jebali ◽  
Arthur Vo-Ha ◽  
Davy Carole ◽  
Mihai Lazar ◽  
Gabriel Ferro ◽  
...  
Keyword(s):  
Contact Resistance ◽  
Ohmic Contacts ◽  
Schottky Barrier Height ◽  
Annealing Temperature ◽  
Process Condition ◽  
Specific Contact Resistance ◽  
High Doping Level ◽  
Annealing Temperatures ◽  
Specific Contact ◽  
P Type

This work reports on the improvement of ohmic contacts made on heavily p-type doped 4H-SiC epitaxial layer selectively grown by Vapor-Liquid-Solid (VLS) transport. Even before any annealing process, the contact is ohmic. This behavior can be explained by the high doping level of the VLS layer (Al concentration > 1020 cm-3) as characterized by SIMS profiling. Upon variation of annealing temperatures, a minimum value of the Specific Contact Resistance (SCR) down to 1.3x10-6 Ω.cm2 has been obtained for both 500 °C and 800 °C annealing temperature. However, a large variation of the SCR was observed for a same process condition. This variation is mainly attributed to a variation of the Schottky Barrier Height.

scholarly journals Rapid systemic surge of IL-33 after severe human trauma: a prospective observational study

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Olav Sundnes ◽  
William Ottestad ◽  
Camilla Schjalm ◽  
Peter Lundbäck ◽  
Lars la Cour Poulsen ◽  
...  
Keyword(s):  
High Resolution ◽  
Prospective Observational Study ◽  
Tissue Injury ◽  
Trauma Patients ◽  
Decoy Receptor ◽  
Interleukin 33 ◽  
Injured Patients ◽  
First Time ◽  
Kinetics Of ◽  
Insight Into

Abstract Background Alarmins are considered proximal mediators of the immune response after tissue injury. Understanding their biology could pave the way for development of new therapeutic targets and biomarkers in human disease, including multiple trauma. In this study we explored high-resolution concentration kinetics of the alarmin interleukin-33 (IL-33) early after human trauma. Methods Plasma samples were serially collected from 136 trauma patients immediately after hospital admission, 2, 4, 6, and 8 h thereafter, and every morning in the ICU. Levels of IL-33 and its decoy receptor sST2 were measured by immunoassays. Results We observed a rapid and transient surge of IL-33 in a subset of critically injured patients. These patients had more widespread tissue injuries and a greater degree of early coagulopathy. IL-33 half-life (t1/2) was 1.4 h (95% CI 1.2–1.6). sST2 displayed a distinctly different pattern with low initial levels but massive increase at later time points. Conclusions We describe for the first time early high-resolution IL-33 concentration kinetics in individual patients after trauma and correlate systemic IL-33 release to clinical data. These findings provide insight into a potentially important axis of danger signaling in humans.

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