Physical parameters associated with the dielectric breakdown of MgO crystals at high temperatures

1984 ◽  
Vol 30 (10) ◽  
pp. 6093-6102 ◽  
Author(s):  
K. L. Tsang ◽  
Y. Chen ◽  
H. T. Tohver
Keyword(s):  
High Temperatures ◽  
Dielectric Breakdown ◽  
Physical Parameters

Silicon oxidation and Si–SiO2 interface of thin oxides

1987 ◽  
Vol 2 (2) ◽  
pp. 216-221 ◽  
Author(s):  
N. M. Ravindra ◽  
J. Narayan ◽  
Dariush Fathy ◽  
J. K. Srivastava ◽  
E. A. Irene
Keyword(s):  
Refractive Index ◽  
High Resolution ◽  
Silicon Oxide ◽  
Dielectric Breakdown ◽  
Oxide Thickness ◽  
Physical Parameters ◽  
Growth Data ◽  
Linear Behavior ◽  
Transmission Electron ◽  
20 Nm

High-resolution transmission electron microscopy (HRTEM) and ellipsometry techniques have been employed to measure thicknesses of silicon oxide, grown at 800°C in dry oxygen, in the thickness range of 2–20 nm. While the oxide growth data measured from TEM obey a nearly linear behavior, those obtained from ellipsometry are seen to vary nonlinearly. The interface structure as function of the increasing oxide thickness was studied using HRTEM. At these oxidation temperatures, the earlier reported variations of roughness at the interface on the oxide thickness for oxides grown at 900°C are not seen. Attempts aimed at correlating the high-resolution transmission electron micrographs with some physical parameters like the refractive index and the dielectric breakdown lead to considerations of the importance of the effect of protrusions of silicon atoms of 1 mm size into SiO2 layers on the interface properties. These findings lead to explanations of some key features concerning the refractive index and density of thin SiO2.

Time-Dependent Dielectric Breakdown in Thin Intrinsic SiO2 Films

1995 ◽  
Vol 386 ◽  
Author(s):  
J. S. Suehle ◽  
P. Chaparala
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
High Temperatures ◽  
Dielectric Breakdown ◽  
Operating Conditions ◽  
Time Dependent ◽  
Stress Tests ◽  
Time Dependent Dielectric Breakdown ◽  
Wide Range ◽  
Very High

ABSTRACTTime-Dependent Dielectric Breakdown studies were performed on 6.5-, 9-, 15-, 20-, and 22.5- nm thick SiO2 films over a wide range of stress temperatures and electric fields. Very high temperatures (400 °C) were used to accelerate breakdown so that stress tests could be performed at low electric fields close to those used for device operating conditions. The results indicate that the dependence of TDDB on electric field and temperature is different from that reported in earlier studies. Specifically, the electric-field-acceleration parameter is independent of temperature and the thermal activation energy was determined to be between 0.7 and 0.9 eV for stress fields below 7.0 MV/cm.Failure distributions of high-quality current-generation oxide films are shown to be of single mode and have dispersions that are not sensitive to stress electric field or temperature, unlike distributions observed for oxides examined in earlier studies. These results have implications on the choice of the correct physical model to describe TDDB in thin films. The data also demonstrate for the first time the reliability of silicon dioxide films at very high temperatures.

EMPIRICAL ESTIMATES OF PHYSICAL PARAMETERS FROM ELECTRICAL RESISTIVITY MEASUREMENTS ON FERRITES

1996 ◽  
Vol 10 (07) ◽  
pp. 299-303
Author(s):  
MISBAH UL ISLAM ◽  
M. SHAKEEL BILAL ◽  
T. ABBAS ◽  
M.U. RANA ◽  
S. MOHSIN RAZA
Keyword(s):  
Electrical Resistivity ◽  
High Temperatures ◽  
Zinc Concentration ◽  
Physical Parameters ◽  
Resistivity Measurements ◽  
Temperature Range ◽  
Octahedral Sites ◽  
Empirical Estimates ◽  
High Zinc ◽  
High Zinc Concentration

Measurements on the electrical resistivity of Mn 1−x Zn x Fe 2 O 4 ferrites with 0<x< 0.15 in the temperature range 300 K <T<450 K , have been carried out. Analysis of the normalised electrical resistivity of these ferrites shows deviations from linearity both at low and high temperatures. There exists a deviation in the electrical resistivity at 300 K at high zinc concentration which may be due to hopping of electrons between Fe +2 and Fe +3 ions at octahedral sites.

Time-Dependent Dielectric Breakdown in Thin Intrinsic SiO2 Films

1995 ◽  
Vol 391 ◽  
Author(s):  
J. S. Suehle ◽  
P. Chaparala
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
High Temperatures ◽  
Dielectric Breakdown ◽  
Operating Conditions ◽  
Time Dependent ◽  
Stress Tests ◽  
Time Dependent Dielectric Breakdown ◽  
Wide Range ◽  
Very High

AbstractTime-Dependent Dielectric Breakdown studies were performed on 6.5-, 9-, 15-, 20-, and 22.5-nm thick SiO2 films over a wide range of stress temperatures and electric fields. Very high temperatures (400 °C) were used to accelerate breakdown so that stress tests could be performed at low electric fields close to those used for device operating conditions. The results indicate that the dependence of TDDB on electric field and temperature is different from that reported in earlier studies. Specifically, the electric-field-acceleration parameter is independent of temperature and the thermal activation energy was determined to be between 0.7 and 0.9 eV for stress fields below 7.0 MV/cm.Failure distributions of high-quality current-generation oxide films are shown to be of single mode and have dispersions that are not sensitive to stress electric field or temperature, unlike distributions observed for oxides examined in earlier studies. These results have implications on the choice of the correct physical model to describe TDDB in thin films. The data also demonstrate for the first time the reliability of silicon dioxide films at very high temperatures.

598 Protection Against Thermal Stress in Humans: Application of “Cooling Wear” Under Heated Conditions in Burn Centers

2020 ◽  
Vol 41 (Supplement_1) ◽  
pp. S142-S142
Author(s):  
Hanna Luze ◽  
Judith Holzer ◽  
Sebastian P Nischwitz ◽  
Lars-Peter Kamolz
Keyword(s):  
Thermal Stress ◽  
High Temperatures ◽  
Manual Dexterity ◽  
Human Organism ◽  
Control Group ◽  
Physical Parameters ◽  
Ambient Temperatures ◽  
Cooling Strategies ◽  
Burn Surgery ◽  
The Impact

Abstract Introduction Many professional groups have to work in places with high temperatures; this includes, for example, doctors and nursing staff working at burn centres. Increased ambient temperature during the care of severely burned patients in the operating theatre and intensive care unit is used to mitigate the loss of thermoregulation, prevent hypothermia, and minimize the impact of hypermetabolism. However, experimental evidence indicates, that even relatively mild thermal stress may affect human performance. Novel cooling strategies have been invented for reducing thermal stress in people, who are occupationally exposed to high temperatures and have for instance already been tested in the military field. Here, the present study investigated the effects of cooling wear on the performance under high ambient temperatures. Methods Effects of cooling wear on concentration and performance of surgeons were investigated in 12 subjects during a simulated burn surgery. Subjects were divided into two groups, one group wearing cooling wear and one control group with normal scrubs. Directly before the exposure to high ambient temperatures, subjects of both groups underwent standardized tests for concentration, manual dexterity and measurements of physiological parameters. After a simulated burn surgery of 1 hour, subjects underwent the same analysing procedure again. Results Results proved that even relatively mild thermal stress affects performance whereby complex actions, that require high concentration, are primarily affected. Initial values of both groups showed approximately homogenous values. After heat exposure, however, subjects who received cooling wear showed higher results in tests for concentration and manual dexterity. Furthermore, the comparison of physical parameters indicates the ability of cooling wear to reduce thermal stress and its’ negative effects on the human organism. Conclusions Decrements in vigilance, performance and endurance are well-documented effects of thermal stress. As an opportunity to withstand thermal stress and therefore improve medical care, cooling wear showed good results in many aspects. Applicability of Research to Practice Based on these promising results cooling strategies may be used as an important tool in medical sectors in the future. Burn medicine may particularly profit from further development and rigorous investigation of cooling strategies.

The influence of interelectronic collisions on conduction and breakdown in polar crystals

1958 ◽  
Vol 246 (1246) ◽  
pp. 406-422 ◽  
Keyword(s):  
High Temperatures ◽  
Electron Scattering ◽  
Indium Antimonide ◽  
Low Temperatures ◽  
Dielectric Breakdown ◽  
Breakdown Field ◽  
Scattering Mechanism ◽  
Momentum Distributions ◽  
Energy And Momentum ◽  
Field Approaches

The variation of the electron mobility with an increasing applied field and also the collective dielectric breakdown field, are calculated assuming that interelectronic collisions are sufficiently frequent to determine the energy and momentum distributions of the electron gas. At high temperatures a small increase (by a factor less than 2) and at low temperatures a large decrease (by a factor greater than 10) in the mobility should be observed as the field approaches the breakdown value. It is also shown that the mobility variation at high temperatures will be substantially the same if interelectronic collisions are not predominant, but at low temperatures there will be no variation at all. The application of these results to semi-conductors where the electron scattering mechanism is uncertain is discussed with special reference to indium antimonide.

Some Results of the Spectroscopic Study of Four Close Binary Systems of Early Spectral Types

1965 ◽  
Vol 5 ◽  
pp. 120-130
Author(s):  
T. S. Galkina
Keyword(s):  
Spectroscopic Study ◽  
Spectral Type ◽  
Spectroscopic Investigation ◽  
Binary Systems ◽  
Quantitative Information ◽  
Close Binary ◽  
Physical Parameters ◽  
Absorption And Emission ◽  
Close Binary Systems ◽  
Quantitative Estimates

It is necessary to have quantitative estimates of the intensity of lines (both absorption and emission) to obtain the physical parameters of the atmosphere of components.Some years ago at the Crimean observatory we began the spectroscopic investigation of close binary systems of the early spectral type with components WR, Of, O, B to try and obtain more quantitative information from the study of the spectra of the components.

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