scholarly journals Feasible Time Evolution Model That Predicts Breakdown in Thin SiO2Films within Unstressed Interval after Constant-Current Stress

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Yasuhisa Omura
Keyword(s):  
Time Evolution ◽  
Oxygen Diffusion ◽  
Transition Process ◽  
Degradation Process ◽  
Evolution Model ◽  
Constant Current ◽  
Water Molecules ◽  
Resistive Transition ◽  
Simple Analytical Model ◽  
Two Stages

This paper proposes a poststress time evolution model for sub-10-nm thick SiO2films for degradation prediction and the extraction of trap-related parameters. The model is based on the understanding that the degradation in thin SiO2films continues within the unstressed interval. The phenomenon is captured by an analytical expression that indicates that the time evolution of SiO2film degradation roughly consists of two stages and that the degradation is more likely to occur if water molecules are present. It is demonstrated that the simple analytical model successfully reproduces measured results. It is also suggested that the degradation process considered here is related to oxygen diffusion in the resistive transition process.

Evaluation of the Degradation Dynamics of Thin Silicon Dioxide Films Using Model-Independent Procedures

1999 ◽  
Vol 592 ◽  
Author(s):  
R. Rodríguez ◽  
M. Nafría ◽  
E. Miranda ◽  
J. Suñé ◽  
X. Aymerich
Keyword(s):  
Silicon Dioxide ◽  
Degradation Process ◽  
Quantitative Information ◽  
Constant Current ◽  
Degradation Model ◽  
Electrical Stress ◽  
Silicon Dioxide Films ◽  
Model Independent ◽  
Thin Silicon ◽  
Mean Time

ABSTRACTThe degradation and breakdown of thin silicon dioxide films has been analysed using a two-step stress method. This procedure allows the evaluation of the degradation induced by the electrical stress without any assumption about the microscopic nature of the degradation process. The method has been used to analyse and compare the degradation dynamics when constant-voltage (CVS) and constant-current stresses (CCS) are applied to the oxide. Moreover, it is shown that in the case of CVS, the fitting of the I-t characteristics can provide quantitative information about the degradation (degradation rate) and breakdown (mean-time-to-breakdown), without taking into account any degradation model.

The decomposition of magnesium hydroxide in an electron microscope

1958 ◽  
Vol 247 (1250) ◽  
pp. 346-352 ◽  
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Electron Diffraction ◽  
Single Crystals ◽  
Magnesium Oxide ◽  
Magnesium Hydroxide ◽  
Basal Plane ◽  
Morphological Changes ◽  
Water Molecules ◽  
Two Stages

The beam of an electron microscope has been used to dehydrate single crystals of magnesium hydroxide to magnesium oxide. Electron diffraction photographs and electron micrographs were taken at various stages to follow the crystallographic and morphological changes which accompany decomposition. The decomposition may be considered to occur in two stages. First, there is a small shrinkage in the basal plane, and the resulting strain causes a maze of cracks in the crystal. This change is followed by a collapse of the planes down the original [0001] of magnesium hydroxide. The collapse is controlled by the migration of water molecules from between the planes to a surface where they can escape. The product is a highly oriented aggregate of micro-crystallites of magnesium oxide. More intense irradiation in the electron beam occasionally causes bulk movement of the solid.

scholarly journals Differential Pulse Voltammetry as an Alternative Method for Tracking Hydrochlorothiazide Electrolytic Degradation

2021 ◽  
Vol 4 (3) ◽  
pp. 70-77
Author(s):  
Mohammad Khanfar
Keyword(s):  
Differential Pulse Voltammetry ◽  
Model Compound ◽  
Differential Pulse ◽  
Degradation Process ◽  
Constant Current ◽  
Solution Ph ◽  
Tracking Method ◽  
First Order Kinetics ◽  
Voltammetric Techniques ◽  
Pulse Voltammetry

This study aims to compare differential pulse voltammetry as a tracking method with chromatography and photometry. The three methods were used to track the degradation of the model compound hydrochlorothiazide (HCT) where 250ml of 0.50mM HCT solution (pH of 3.50 and ionic strength of 0.010M) was electrolyzed with 50.0mAmp constant current. The degradation process demonstrated great fit (R2 >0.99) with pseudo-first-order kinetics when the three tracking methods were utilized. However, different rate constants were reported for these methods: 0.032min-1, 0.016 min-1, and 0.0052min-1 for the chromatographic, photometric, and voltammetric techniques, respectively. The observed variation was attributed to the nature of the utilized probing methods. The differential pulse voltammetry is promising as an electrolytic decomposition tracking method; however, the working probe to target pollutants needs to be improved.

scholarly journals DTA Evaluation of Spruce Wood Degradation Process

2017 ◽  
Vol 25 (40) ◽  
pp. 41-48
Author(s):  
Ivan Hrušovský ◽  
Peter Rantuch ◽  
Jozef Martinka ◽  
Simona Dzíbelová
Keyword(s):  
Activation Energy ◽  
Room Temperature ◽  
Degradation Process ◽  
Heating Rates ◽  
Wood Degradation ◽  
Wood Sawdust ◽  
Spruce Wood ◽  
Calculated Activation Energy ◽  
Two Stages ◽  
Calculated Activation

Abstract The decomposition stages of spruce wood sawdust were analyzed by means of sequential differential calorimetry. Two stages of decomposition were identified and activation energy of one stage was calculated using the Kissinger method. The DTA was conducted by means of SEDEX safety calorimeter. Sample was analyzed under three heating rates of 10, 20 and 45 °C/h in temperature range from room temperature to 400 °C. The calculated activation energy for the last and most clear decomposition peak was 122.63 KJ/mol. The results are comparable with the data calculated by J.V. Rissanen et al., who calculated activation energy for Spruce hemicellulose as 120 KJ/mol.

scholarly journals A discrete-time-evolution model to forecast progress of Covid-19 outbreak

PLoS ONE ◽  
2020 ◽  
Vol 15 (10) ◽  
pp. e0241472 ◽  
Author(s):  
Evaldo M. F. Curado ◽  
Marco R. Curado
Keyword(s):  
Time Evolution ◽  
Discrete Time ◽  
Evolution Model

scholarly journals High-Temperature Surface Oxide Growth Kinetics of Al–Si–Zr Bulk Alloys and Ribbons

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1893
Author(s):  
Denitsa Kiradzhiyska ◽  
Gueorgui Vassilev ◽  
Rositsa Mancheva ◽  
Svetlana Yaneva ◽  
Nikolina Milcheva
Keyword(s):  
High Temperature ◽  
Oxygen Diffusion ◽  
Surface Oxidation ◽  
Trace Level ◽  
Thermogravimetric Method ◽  
Modification Technique ◽  
Two Stages ◽  
Bulk Alloys ◽  
Kinetics Of ◽  
Temperature Surface

A typical modification technique of the functional properties of Al–Si based alloys is the addition of some third element in trace level. In the present work, ternary Al–Si–Zr bulk and ribbon alloys have been prepared. The kinetics of high-temperature surface oxidation has been studied by thermogravimetric method. It was found that at the start of the experiment the chemical reaction velocity is rate-controlling while for longer times the (oxygen) diffusion is the rate-controlling process. Activation energy of the two stages of oxidation has been obtained. Additional studies such as thermochemical analysis, optical and electron microscopy, and microhardness tests have been done.

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