Investigation of Midgap Defects in GaAs Induced By Heat-Treatment (EL2), Electron-Irradiation, and Plastic Deformation

1987 ◽  
Vol 104 ◽  
Author(s):  
Toru Haga ◽  
Masashi Suezawa ◽  
Koji Sumino
Keyword(s):  
Heat Treatment ◽  
Plastic Deformation ◽  
Low Temperature ◽  
Electron Irradiation ◽  
Grown Crystal ◽  
Isothermal Annealing ◽  
Rate Equations ◽  
Kinetics Of ◽  
Absorption Measurements ◽  
Chemical Rate

ABSTRACTThermal behavior of midgap defects generated in GaAs by different procedures has been followed by means of optical absorption measurements at low temperature. EL2 centers existing in as-grown crystals or generated by thermal annealing at temperatures lower than about 1000°C, which are characterized by a perfectly quenchable absorption at a wavelength of 1.0 μm, are found to diminish at temperature higher than 1000°C. The generation kinetics of EL2 centers has been traced during isothermal annealing of a crystal in which grown-in EL2 centers have previously been eliminated by annealing at 1200°C. The result of an analysis with the use of simplified chemical rate equations favors the model that an EL2 center is composed of an As antisite and two Ga vacancies. Both quenchable and unquenchable absorptions are associated with the midgap defects induced by plastic deformation or electron -irradiation. Isochronal annealing reveals that such defects are not identical with EL2 centers that are found in an as-grown crystal even if they accompany the quenchable absorption.

Change in the Parameters of Electron-Irradiated 4H-SiC Schottky Diodes as a Function of the Time during Low-Temperature Isothermal Annealing

2019 ◽  
Vol 963 ◽  
pp. 734-737
Author(s):  
Oleg Korolkov ◽  
Vitalii V. Kozlovski ◽  
Alexander A. Lebedev ◽  
Jana Toompuu ◽  
Natalja Sleptsuk ◽  
...  
Keyword(s):  
Low Temperature ◽  
Thermal Cycling ◽  
Liquid Nitrogen ◽  
Isothermal Annealing ◽  
Schottky Diodes ◽  
Rapid Cooling ◽  
Dlts Spectrum ◽  
Low Temperature Annealing ◽  
Kinetics Of ◽  
Dlts Spectra

In the present work, the kinetics of low-temperature annealing (400 °C) of 4H-SiC JBS diodes irradiated by electrons with an energy of 0.9 MeV and with a dose of 1E16 cm-2 was studied. The dynamics of changes in I-V, C-V characteristics, as well as DLTS spectra are shown. In the course of the work, a thermal cycling effect was discovered, i.e., effect of multiple rapid cooling to the temperature of liquid nitrogen and heating of the samples. As a result of thermal cycling, the barrier capacity increases and the on-resistance (Rs) decreases. In the DLTS spectrum, a level of - 0.38 eV appears, absent in the as-irradiated diodes.

Nature of Charged Metastable Defects in Network Rebonding Model

2002 ◽  
Vol 715 ◽  
Author(s):  
R. Biswas ◽  
B. C. Pan
Keyword(s):  
Low Temperature ◽  
Rate Equations ◽  
Atomistic Model ◽  
Dangling Bonds ◽  
Defect Creation ◽  
Higher Temperature ◽  
Kinetics Of Degradation ◽  
Kinetics Of ◽  
Defect Densities ◽  
Positively Charged

AbstractWe recently developed an atomistic model of metastability of a-Si:H, where defect creation is driven by the breaking of weak silicon bonds. The kinetics of degradation in this model is simulated with coupled rate equations that show t1/3 kinetics of defect creation and saturation behavior similar to experiment. Saturated defect densities of neutral dangling bonds are accompanied by a much smaller density of negatively charged floating bonds and positively charged dangling bonds (D+). We propose a two-step annealing mechanism where the positively charged D+ dangling bonds are annealed at low temperature and the D0 at higher temperature -which accounts for hysteresis in mobility lifetime products.

New Decisions in Manufacturing Techniques of the Cemented Parts of Cars

2018 ◽  
Vol 284 ◽  
pp. 1226-1229
Author(s):  
T.V. Shveyova ◽  
V.I. Astashchenko ◽  
A.I. Shveyov
Keyword(s):  
Heat Treatment ◽  
Low Temperature ◽  
Isothermal Annealing ◽  
Hot Stamping ◽  
Preliminary Heat Treatment ◽  
Thermal Processes ◽  
Rational Scheme ◽  
Minimum Change ◽  
Manufacturing Techniques

The unused reserves of metal and manufacturing techniques of forgings and hardening of products promoting minimization and stabilization of deformation and a buckling of gear details are revealed. Need of rationing of size of a hardenability of steel, a regulation of speed of cooling of forgings after hot stamping and application of isothermal annealing as preliminary heat treatment is established. The rational scheme of laying and technology of low-temperature cementation of pinion gears providing the minimum change of the geometrical sizes of details in chemical and thermal processes is offered.

THE EFFECT OF HEAT TREATMENT ON LOW TEMPERATURE INTERNAL FRICTION MAXIMA

1958 ◽  
Vol 36 (1) ◽  
pp. 82-87 ◽  
Author(s):  
T. S. Hutchison ◽  
G. J. Hutton
Keyword(s):  
Heat Treatment ◽  
Plastic Deformation ◽  
Melting Point ◽  
Low Temperature ◽  
Internal Friction ◽  
High Purity ◽  
Temperature Relation ◽  
Temperature Range ◽  
High Purity Aluminum

Measurements of the attenuation of sound at a frequency of 5 megacycles have been made over the temperature range 100° to 200 ° K. on polycrystalline high purity aluminum subjected to various thermal and mechanical treatments. With samples annealed at 520 °C. a maximum in the attenuation versus temperature relation had been observed at 155 ° K. This maximum was greatly increased by small amounts of plastic deformation of the order of 1.0 to 1.5%.Aluminum initially annealed for extended periods at temperatures much closer to the melting point shows, however, either no increase in the attenuation maximum at 155 ° K. or, in extreme cases, no maximum in this region at all, after plastic deformation of the same order as before. It is believed that this indicates a dependence of the deformation-induced maximum on the distribution and possibly on the number of dislocations in the metal prior to deformation and on the arrangement of the dislocations after deformation.

Effect of Solution Annealing and Low Temperature Ageing on the Microstructures and Superelastic Behaviour of Ti-50.7at.%Ni Alloy

2013 ◽  
Vol 813 ◽  
pp. 72-80
Author(s):  
Esah Hamzah ◽  
Kurnia Hastuti ◽  
Jasmi Hashim ◽  
Chuan Eng Chuah ◽  
Muhammad Adil Khattak
Keyword(s):  
Heat Treatment ◽  
Plastic Deformation ◽  
Low Temperature ◽  
Testing Temperature ◽  
Sample Solution ◽  
Solution Annealing ◽  
Treatment Conditions ◽  
Ni Alloy ◽  
Temperature Ageing ◽  
Higher Temperature

In this study a plate form of Ti-50.7at.%Ni was subjected to solution annealing at 800°C and 900°C for one hour followed by ageing at 300°C and 400°C for 4 hours respectively in order to investigate the effect of solution annealing and low temperature ageing on the microstructures and superelastic behaviour. It was found that the formation of Ti3Ni4 precipitates on the samples aged at 300°C and 400°C influences superelasticity differently. Increasing the testing temperature up to 38°C generally increases the superelasticity of samples for all heat treatment conditions compared to those tested at 22°C, however the sample solution annealed at 900°C give better superelasticity at 22°C due to excessive plastic deformation at higher temperature.

PLASTIC DEFORMATION OF SILICON AT LOW TEMPERATURE AND THE INFLUENCE OF DOPING

1983 ◽  
Vol 44 (C4) ◽  
pp. C4-243-C4-253 ◽  
Author(s):  
J. Rabier ◽  
P. Veyssière ◽  
J. L. Demenet
Keyword(s):  
Plastic Deformation ◽  
Low Temperature

The low temperature aluminising kinetics of hot-work tool steels

2012 ◽  
Vol 67 (2) ◽  
pp. 133-139
Author(s):  
B. Matijević ◽  
I. Kumić ◽  
T. Belić
Keyword(s):  
Low Temperature ◽  
Tool Steels ◽  
Kinetics Of ◽  
Hot Work Tool Steels

JESSAIR

Alloy Digest ◽  
1965 ◽  
Vol 14 (1) ◽  
Keyword(s):  
Heat Treatment ◽  
Fracture Toughness ◽  
Low Temperature ◽  
Physical Properties ◽  
Heat Treating ◽  
Bend Strength ◽  
Steel Company ◽  
Temperature Heat ◽  
Temperature Heat Treatment ◽  
Manganese Chromium

Abstract Jessair is a manganese, chromium, molybdenum alloy steel combining the deep harding characteristics of air-hardening steels with the simplicity of low temperature heat treatment possible in many oil-hardening steels. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and bend strength as well as fracture toughness and fatigue. It also includes information on forming, heat treating, machining, and joining. Filing Code: TS-157. Producer or source: Jessop Steel Company.

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