Helium and Hydrogen Induced Growth of Microcavities in Silicon; Application to Gas And Impurity Collection

1994 ◽  
Vol 373 ◽  
Author(s):  
A. Van Veen ◽  
H. Schut ◽  
R.A. Hakvoort ◽  
A. Fedorov ◽  
K.T. Westerduin

AbstractThermal helium desorption spectrometry and positron beam analysis have been used to monitor the growth of helium vacancy clusters during room temperature helium irradiation of silicon and during subsequent annealing to 1300 K. Experimental results obtained with hydrogen irradiation show that also hydrogen can be used to create cavities. There is a rather sharp threshold dose for creating cavities that will survive 1300 K annealing. It appears that positrons form a sensitive probe for the trapping and release of impurities inside the cavities. Results of atomistic calculations are used to discuss thermal stability of helium vacancy complexes. The results are related to recent impurity gettering studies based on impurity trapping at helium induced gettering centers.

2017 ◽  
Vol 71 (12) ◽  
pp. 2626-2631 ◽  
Author(s):  
Jeffrey L. Wheeler ◽  
McKinley Pugh ◽  
S. Jake Atkins ◽  
Jason M. Porter

In this work, the thermal stability of the room temperature ionic liquid (RTIL) 1-ethyl-3-methylimidazolium ethylsulfate ([EMIM][EtSO4]) is investigated using infrared (IR) spectroscopy. Quantitative IR absorption spectral data are measured for heated [EMIM][EtSO4]. Spectra have been collected between 25 ℃ and 100 ℃ using a heated optical cell. Multiple samples and cell pathlengths are used to determine quantitative values for the molar absorptivity of [EMIM][EtSO4]. These results are compared to previous computational models of the ion pair. These quantitative spectra are used to measure the rate of thermal decomposition of [EMIM][EtSO4] at elevated temperatures. The spectroscopic measurements of the rate of decomposition show that thermogravimetric methods overestimate the thermal stability of [EMIM][EtSO4].


2018 ◽  
Vol 9 (1) ◽  
pp. 39-49 ◽  
Author(s):  
Sharifah Nurul Ain Syed Hashim ◽  
Sarani Zakaria ◽  
Chin Hua Chia ◽  
Sharifah Nabihah Syed Jaafar

In this study, soda alkali lignin from oil palm empty fruit bunch (EFB-AL) and kenaf core (KC-AL) are esterified with maleic anhydride under two different conditions, namely i) pyridine at temperature of 120°C for 3h and ii) aqueous alkaline solution at room temperature for 4h. As a result, the weight percentage gain (WPG) of the esterified EFB-AL (EFB-EL) and esterified KC-AL (KC-EL) in pyridine demonstrated a higher compared to aqueous alkaline solution. The FT-IR results of EFB-EL and KC-EL in both solvents exhibited some changes at the carbonyl and hydroxyl groups. Furthermore, the esterification process induced the carboxylic peak to appear in both alkali lignin samples. The outcome is confirmed by conducting H-NMR analysis, which demonstrated ester and carboxylic acid peaks within the spectral analysis. Finally, the TGA results showed both EFB-EL and KC-EL that are exposed to aqueous alkaline actually possessed better thermal stability and higher activation energy (Ea) compared to the esterified samples in pyridine.


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.


2011 ◽  
Vol 2011 (HITEN) ◽  
pp. 000196-000200 ◽  
Author(s):  
Kenji Okamoto ◽  
Yuji Takematsu ◽  
Miyako Hitomi ◽  
Yoshinari Ikeda ◽  
Yoshikazu Takahashi

There is a demand to improve the thermal stability of epoxy molding resins used in the power module of SiC power chips operating at temperatures of 200°C or more. This paper describes a technique for increasing the thermal stability of the resin by decreasing molecular motion through the addition of nanofiller. The experimental results showed that the glass transition temperature (Tg) of the epoxy resin increased by approximately 30°C when the silica nanofiller was added. The epoxy resin added nanofiller was investigated in order to achieve the operation temperature 200°C of power module.


2007 ◽  
Vol 561-565 ◽  
pp. 2399-2402
Author(s):  
Yoshihisa Kaneko ◽  
H. Sakakibara ◽  
Satoshi Hashimoto

Co/Cu and Ni/Cu multilayers fabricated by electroplating technique were annealed at various temperatures in order to investigate thermal stability of multilayered structures. Vickers hardness tests on the annealed Co/Cu and Ni/Cu multilayers were conducted at room temperature. It was recognized that after the annealing at 1023K the Co/Cu multilayer still maintained the hardness of as-deposited state. On the other hand, the hardness of Ni/Cu multilayer was almost identical to copper substrate after the annealing at 903K.


2013 ◽  
Vol 275-277 ◽  
pp. 2375-2380 ◽  
Author(s):  
Fei Li ◽  
Shao Jun Wang ◽  
Li Wei ◽  
Wei Na Tao ◽  
Xue Yang Dong ◽  
...  

The electrolyte optimum composition consists of 1mol/L LiTFSI in the [EMIM]+[TFSI]-mixed with EC and DMC in weight ratio of 60:20:20. The LiFePO4/Li cell using 1 mol/L LiTFSI/([EMIM]+[TFSI]-/EC/DMC) as electrolyte show that the first coulomb efficiency was 90% and the first discharge capacity was 168mAh g-1. The 15th reversible capacities were maintain 157mAh g-1at 0.2C. Compared with traditional organic electrolyte and pure IL electrolyte, IL-based mixed electrolyte have good coulomb efficiencies and higher charge and discharge performances. The lithium transference number of IL-based mixed electrolyte at room temperature are 0.59. Thermal stability of IL-based mixed electrolyte higher than traditional organic electrolyte, and show almost non-flammability by the burning tests.


1994 ◽  
Vol 337 ◽  
Author(s):  
F. Ren ◽  
C. R. Abernathy ◽  
S. J. Pearton ◽  
P. W. Wisk

ABSTRACTExtremely low contact resistance of non-alloyed Ti/Pt/Au metallization on n-type InN is demonstrated. The contacts were annealed at different temperatures up to 420 °C to investigate their thermal stability. A low contact resistivity of 1.8 x 10-7 ohm-cm2 was measured at room temperature using the transmission line method. This was due to the extremely high doping level (5 x 1020 cm-3) in the InN. After 300 °C annealing, the contact resistivity increased to 2.4 x 10-7 ohm-cm2- For 360 °C annealing, the contact morphology showed some degradation, but the contact resistivity was almost the same as at 300 °C. There was serious degradation of the contacts after 420 °C annealing. The morphology became very rough, and the contact and sheet resistances increased by factors of 3-5 times. This degradation is believed due to the decomposition of the InN film. The contact resistivities between n-type epitaxial GaAs and InN were also investigated, and showed values around 10-4 ohm-cm2.


1975 ◽  
Vol 38 (8) ◽  
pp. 473-475 ◽  
Author(s):  
R. SULLIVAN ◽  
R. M. MARNELL ◽  
E. P. LARKIN ◽  
R. B. READ

Thermal stability of two enteroviruses, poliovirus 1 and coxsackievirus B-2, inoculated into ground beef patties was investigated using household broiling procedures. Internal temperatures during cooking were monitored by thermocouples placed in the centers of patties. The appearance of the centers of hamburgers correlated with the temperatures reached: red-pink-rare, 60 C (140 F); pink-brown-medium, 71 C (160 F); and brown-well-done, 76.7 C (170 F). Cooked and uncooked virus-inoculated patties were assayed for viral plaque forming units produced in Vero monkey kidney cell cultures. No viruses were detected in patties cooked to 60 C (140 F) and held at room temperature for 3 min. However, virus was recovered from 8 of 24 patties cooked to 60 C (140 F) and immediately cooled to 23 C (74 F). No viruses were detected in patties heated to 71 C (160 F) or 76.7 C (170 F) internal temperatures. Results indicate that the cooking time and temperatures used to prepare rare hamburgers wherein the center meat remains red may not be sufficient to inactivate viruses that might be present in the sample especially if the hamburger is consumed or cooled within 3 min of cooking. When frozen or partially defrosted patties are cooked, extensive external cooking can occur with little or no visible change in the coloration of the center meat.


1994 ◽  
Vol 354 ◽  
Author(s):  
P J Hughes ◽  
E H Li ◽  
B L Weiss ◽  
H E Jackson ◽  
J S Roberts

AbstractThe effects of interdiffusion on the band structure of two MxGaUxAs/GaAs single quantum well (SQW) structures were studied using room temperature photoreflectance. Rapid thermal annealing of the SQW structures at temperatures of 800°C, 900°C and 1000°C for times up to 180 seconds resulted in limited interdiffusion. Low dose (1014 cm”2) oxygen implantation reduced the thermal stability of these structures where the extent of the interdiffusion was found to be greater for the implanted samples for identical annealing conditions.


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