Thermal Stability of Strained InGaAs/GaAs Single Quantum Wells

1989 ◽  
Vol 160 ◽  
Author(s):  
B. Elman ◽  
Emil S. Koteles ◽  
P. Melman ◽  
C.A. Armiento ◽  
C. Jagannath

AbstractWe present a study of the structural stability of InGaAs/GaAs strained single quantum wells (SQW) grown with a variety of indium compositions and with well widths close to critical thickness values. The samples were grown by molecular beam epitaxy and were subjected to furnace annealing as well as ion implantation followed by rapid thermal annealing. Changes in low temperature photoluminescence linewidths were used to evaluate the stability of strained SQWs. We observed both strain relief, in wide SQWs and strain recovery, in higher indium composition narrow quantum wells which were partially relaxed (low dislocation density) as-grown.

1995 ◽  
Vol 405 ◽  
Author(s):  
F. Hyuga ◽  
T. Nittono ◽  
K. Watanabe ◽  
T. Furuta

AbstractThermal stabilities of GaAs/InGaP and InGaP/(In)GaAs interfaces are investigated using InGaP/(In)GaAs/InGaP single quantum wells. Annealing is performed at a temperature range between 600 and 900 °C for 10 min. Positions and the full widths at half maximum (FWHM) of photoluminescence (PL) peaks are almost identical to those of as-grown ones up to 800 °C. Blue shifts of PL peaks and increased widths of their FWHM observed after 900 °C annealing are suppressed by shortening the annealing time to 0.1 sec. Annealing at 900 ‘C for 0.1 sec is sufficient to activate Si ions implanted into (In)GaAs layers. As a result, these thermal stabilities are able to provide high reliability and high performance of InGaP/(In)GaAs heterostructure MESFET ICs.


1990 ◽  
Vol 112 (1) ◽  
pp. 10-15 ◽  
Author(s):  
M. I. Flik ◽  
C. L. Tien

Intrinsic thermal stability denotes a situation where a superconductor can carry the operating current without resistance at all times after the occurrence of a localized release of thermal energy. This novel stability criterion is different from the cryogenic stability criteria for magnets and has particular relevance to thin-film superconductors. Crystals of ceramic high-temperature superconductors are likely to exhibit anisotropic thermal conductivity. The resultant anisotropy of highly oriented films of superconductors greatly influences their thermal stability. This work presents an analysis for the maximum operating current density that ensures intrinsic stability. The stability criterion depends on the amount of released energy, the Biot number, the aspect ratio, and the ratio of the thermal conductivities in the plane of the film and normal to it.


Author(s):  
Stephanie Saalfeld ◽  
Thomas Wegener ◽  
Berthold Scholtes ◽  
Thomas Niendorf

AbstractThe stability of compressive residual stresses generated by deep rolling plays a decisive role on the fatigue behavior of specimens and components, respectively. In this regard, deep rolling at elevated temperature has proven to be very effective in stabilizing residual stresses when fatigue analysis is conducted at ambient temperature. However, since residual stresses can be affected not only by plastic deformation but also when thermal energy is provided, it is necessary to analyze the influence of temperature and time on the relaxation behavior of residual stresses at elevated temperature. To evaluate the effect of deep rolling at elevated temperatures on stability limits under thermal as well as combined thermo-mechanical loads, the present work introduces and discusses the results of investigations on the thermal stability of residual stresses in differently deep rolled material conditions of the steel SAE 1045.


2002 ◽  
Vol 299 (1) ◽  
pp. 79-84 ◽  
Author(s):  
M Xu ◽  
C.X Liu ◽  
H.F Liu ◽  
G.M Luo ◽  
X.M Chen ◽  
...  

2021 ◽  
Vol 233 ◽  
pp. 02046
Author(s):  
Xiaoxue Fan ◽  
Ming Cheng ◽  
Xiaoning Zhang ◽  
Cunfang Wang ◽  
Hua Jiang

This paper aimed to evaluate the changes in the thermal stability of goat milk, cow milk and homogenized milk under different pH conditions. The results showed that goat milk was of type B milk, and the thermal stability were positively correlated with the pH value. But cow milk was of type A milk, the most stable pH of fresh milk was 6.9, while it was 6.7 for homogenized cow milk. Compared with cow milk, the acidification of goat milk was stronger due to heat. Therefore, in the process of milk production, the germicidal heating conditions of two different milk sources should be determined according to their thermal stability.


1989 ◽  
Vol 173 ◽  
Author(s):  
Michiya Otani ◽  
Sugio Otani

ABSTRACTThe stability of the magnetic properties of dehydrogenated triaryl-methane resins was investigated both at room temperature and at elevated temperatures. A magnetic property different from that reported in a previous paper was found in the course of studying the reproducibility of synthesis. This new property was examined through a mechanical response of the resins to a set of permanent magnets.


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