A Generalized Model of the Yield Drop for Impure Semiconductors

2001 ◽  
Vol 683 ◽  
Author(s):  
Boris V. Petukhov
Keyword(s):  
Rate Sensitivity ◽  
Internal Stresses ◽  
Yield Drop ◽  
Solution Hardening ◽  
Silicon Crystals ◽  
Semiconductor Crystals ◽  
Float Zone ◽  
Age Dependent ◽  
Initial Dislocation Density ◽  
Kinetics Of

ABSTRACTThe Alexander-Haasen theory describing the deformation behavior of low-dislocated semiconductor crystals is generalized taking into account the dynamic ageing of dislocations due to the impurities dragging. The constitutive equations describing kinetics of the plastic deformation are modified for the case of a spectrum of age-dependent internal stresses. Besides the solution hardening, the theory developed explains a number of qualitative distinctions of the elastic-plastic transition in silicon crystals grown by the Czochralski and the float zone methods. Particularly, this concerns a dependence of the yield drop on the initial dislocation density, and a weakening of the strain rate sensitivity of the yield stress.

Passage rate of solids and fluids in the digestive tract of buffaloes, cattle and sheep: selection of non-linear model

1997 ◽  
Vol 64 (1) ◽  
pp. 63-69 ◽  
Author(s):  
A. Amici ◽  
S. Bartocci ◽  
S. Terramoccia ◽  
F. Martillotti
Keyword(s):  
Linear Models ◽  
Latin Square ◽  
Sums Of Squares ◽  
Passage Rate ◽  
Significant Difference ◽  
Age Dependent ◽  
Non Linear ◽  
Best Fitting ◽  
Kinetics Of ◽  
Selection Of

AbstractFive mathematical models were compared to select the most satisfactory model to describe digesta kinetics of solids and fluids in the gastrointestinal tract of buffaloes (Mediterranean bulls), cattle (Friesian bulls) and sheep (Delle Langhe rams) given food at maintenance level, according to a Latin-square arrangement for four consecutive periods of 21 days. Chromium mordanted alfalfa hay and cobalt-ethylenediamine tetraacetic acid were used as nonabsorbable markers and were administered through the rumen cannula in a single dose. Four different isonitrogenous diets (N × 6·25 = 140 g/kg dry matter) with different concentrate:forage ratios (12·5:87·5, 25:75, 37·5:62·5, 50:50) were used.Faecal chromium and cobalt concentration curves were fitted with five non-linear models: three gamma (G2, G3, G4) age-dependent one-compartment, one gamma age-dependent/age-independent two-compartment (G2G1) and one multicompartment (MC).Wilcoxon tests on residual sums of squares of the different models for solids showed that MC and G4 gave a better fit than G2G1, G2, G3 for all the data and within the species. The comparison of MC v. G4 did not show any significant difference (P > 0·05) for all the data computed together or within each species. Nevertheless, MC had a higher number of curves with lower residual sums of squares in comparison with G4 and was also able to produce estimates of digesta kinetics in the second compartment.The cobalt excretion curves for fluids, considering all the data, and only within sheep, showed G4 as the best fitting model. When G4 was compared with other models no significant differences were recorded either for cattle: G4 v. G2 (F = 0·6645), G4 v. G2G1 (P = 0·0620) and for buffalo: G4 v. G2 (P = 0·1575), G4 v.G3(P = 0·0796) and G4 v. G2G1 (P = 0·1641).It is concluded that the multicompartment model (MC) and G4 model were the best fits for solids and for fluids respectively.

Study of “Reverse Annealing” of Boron Under Low Temperature Lamp Anneals

1985 ◽  
Vol 52 ◽  
Author(s):  
J. Huang ◽  
R. J. Jaccodine
Keyword(s):  
Annealing Temperature ◽  
Halogen Lamp ◽  
Electron Microscopic ◽  
Cross Sectional ◽  
Temperature Range ◽  
Silicon Crystals ◽  
Float Zone ◽  
Transmission Electron ◽  
Effect Of Oxygen ◽  
Tungsten Halogen Lamp

ABSTRACTThe reverse annealing of ion implanted boron, namely, the decrease in the concentration of electrically active boron as the isochronal annealing temperature increases, occurs in the temperature range from 550 to 650°C during conventional furnace heating. In this study, silicon crystals were boron implanted at 50 Kev to a dose of 1×1015 cm-2 followed by both furnace and tungsten-halogen lamp annealing in the reverse annealing temperature range. Cross-sectional Transmission electron microscopic (TEM) technique was used to examine the microstructural changes during annealing as a function of depth. Sheet resistance measurements gave a quick check of the electrical properties, while spreading resistance profiling with shallow angle lapping and Hall measurements reveals the mobility and carrier concentration as a function of depth. Czochralski and Float Zone crystals were studied to examine the effect of oxygen. Tungsten-halogen lamp thermal processing was found to have a more pronounced effect on the annealing of secondary defects than did furnace annealing. The reverse annealing of boron was eliminated completely for lamp annealing time as short as 60 seconds.

Mechanical Strength of Oxygen-Doped Float-Zone Silicon Crystals

1980 ◽  
Vol 19 (12) ◽  
pp. L763-L766 ◽  
Author(s):  
Koji Sumino ◽  
Ichiro Yonenaga ◽  
Atsushi Yusa
Keyword(s):  
Mechanical Strength ◽  
Silicon Crystals ◽  
Float Zone

A Progress in Gold Nanoparticles: Adsorption Behavior

2012 ◽  
Vol 557-559 ◽  
pp. 530-533
Author(s):  
Da Ming Ban ◽  
Ze Quan Liu ◽  
Yang Min
Keyword(s):  
Gold Nanoparticles ◽  
Adsorption Kinetics ◽  
Organic Molecules ◽  
Adsorption Behavior ◽  
Self Assembled Monolayers ◽  
Adsorption Characteristics ◽  
Semiconductor Crystals ◽  
Assembled Monolayers ◽  
Recent Developments ◽  
Kinetics Of

This perspective reviews recent developments in the adsorption behavior and the adsorption kinetics of gold nanoparticles(AuNPs),with emphasis on papers initiating the developments and with an eye to their consequences. The aspect adsorption behavior of organic molecules on AuNPs have included the adsorption pattern of thionine, 1,4-PDI , 4-Methoxypyr-idine, 1,2,3-triazole and SH-PEG5K and the influence of adsorption. The aspect adsorption characteristics of biomolecules on AuNPs have included the adsorption kinetics of single-stranded DNA and proteins on the AuNPs. The last key aspect adsorption AuNPs on self-assembled monolayers have included the adsorption kinetics of AuNPs on different SAMs and semiconductor crystals.

scholarly journals Распад твердого раствора межузельного магния в кремнии

2019 ◽  
Vol 53 (3) ◽  
pp. 314
Author(s):  
В.Б. Шуман ◽  
А.Н. Лодыгин ◽  
Л.М. Порцель ◽  
А.А. Яковлева ◽  
Н.В. Абросимов ◽  
...  
Keyword(s):  
Activation Energy ◽  
Solid Solution ◽  
Single Crystal ◽  
Diffusion Activation Energy ◽  
Practical Application ◽  
Float Zone ◽  
Sandwich Method ◽  
Kinetics Of ◽  
Diffusion Activation

AbstractThe decomposition of a solid solution of interstitial magnesium Mg_ i in silicon is studied. Float-Zone dislocation-free single-crystal n -Si with a resistivity of ~8 × 10^3 Ω cm and oxygen and carbon contents of ~5 × 10^14 cm^–3 and ~1 × 10^15 cm^–3 is used in the experiments. The samples are doped using the diffusion sandwich method at T =1100°C followed by quenching. Decomposition of the supersaturated Mg_ i solid solution is studied by observing the kinetics of increasing the resistivity of doped samples resulting from their annealing in the range T = 400–620°C. It is found that the decomposition is characterized by an activation energy of E _ a ≈ 1.6 eV, which is close to the previously determined diffusion activation energy of Mg_ i in silicon. It is also shown that Si:Mg exhibits stable properties at temperatures not exceeding 400°C, which is important for its possible practical application.

scholarly journals Analytical models of austenite transformation in steel with allowance for internal stresses

2018 ◽  
pp. 371-383
Author(s):  
S.V. Bobyr
Keyword(s):  
Experimental Data ◽  
Heat Treatment ◽  
Experimental Study ◽  
Hot Deformation ◽  
Structural Transformations ◽  
Analytical Models ◽  
Theoretical Expression ◽  
Internal Stresses ◽  
Kinetics Of ◽  
Comprehensive Study

The aim of the work is to review the analytical models of austenite decay, taking into account the internal stresses obtained by various authors. It is shown that a common drawback of the known works is the neglect of the effect of the stress-strain state arising during the heat treatment of parts on the kinetics of structural transformations, while the available experimental data indicate a significant effect of stresses and strains on structural transformations. It has been established that the experimental data accumulated to date do not allow reliably describing the effect of the stress state on structural transitions during the heat treatment of steels for the hot deformation tool. A simple theoretical expression is proposed for calculating the amount of martensite formed as a function of the voltage in the γ phase. It is theoretically shown that taking into account the voltage acting in the γ phase leads to an increase in the temperature of the end of the formation of martensite. Experimental study of this effect is especially convenient to carry out in isothermal conditions under uniaxial tension. It is shown that in order to reliably predict the structural state of the hot deformation tool during heat treatment, it is necessary to conduct a comprehensive study related to the experimental study of the effect of stresses on all types of transformations and the creation of an adequate mathematical model of austenite decomposition based on the obtained experimental data.

Kinetics of Internal Stresses of Water Varnishes

2021 ◽  
pp. 348-358
Author(s):  
Izet Horman ◽  
Esad Azemović ◽  
Amina Pandžo
Keyword(s):  
Internal Stresses ◽  
Kinetics Of
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