scholarly journals Experimental Investigation of Electro-thermal Stress Impact on SiC-BJTs Electrical Characteristics

2013 ◽  
Vol 2013 (HITEN) ◽  
pp. 000290-000297
Author(s):  
Thibaut Chailloux ◽  
Cyril Calvez ◽  
Pascal Bevilacqua ◽  
Dominique Planson ◽  
Dominique Tournier
Keyword(s):  
Thermal Stress ◽  
High Temperature ◽  
Room Temperature ◽  
Thermal Stresses ◽  
Temperature Cycling ◽  
Bipolar Junction Transistors ◽  
Electrical Characteristics ◽  
Switching Operation ◽  
Operation Temperature ◽  
The Stability

The aim of this study consists in investigating the effects of electrical and thermal stresses on SiC n-p-n bipolar junction transistors (BJTs). The stability of the electrical characteristics of BJTs is inspected under switching operation, DC operation, temperature cycling and continuous thermal stress up to 225°C. While switching operation and temperature cycling for several hours lead to significant changes at 25°C, the electrical characteristics were little degraded at high temperature. Besides, DC operation and continuous thermal stress did not result in significant degradation at all, both at room temperature and at high temperature.

ARSENIDES OF THE TRANSITION METALS: II. THE NICKEL ARSENIDES

1957 ◽  
Vol 35 (10) ◽  
pp. 1205-1215 ◽  
Author(s):  
R. D. Heyding ◽  
L. D. Calvert
Keyword(s):  
High Temperature ◽  
Melting Point ◽  
Transition Metals ◽  
Stability Region ◽  
Room Temperature ◽  
Metastable Phase ◽  
The Other ◽  
Incongruent Melting ◽  
Diffraction Patterns ◽  
The Stability

Alloys of nickel and arsenic containing up to 60% As by weight have been studied by means of room temperature and high temperature Debye-Scherrer diagrams. Three compounds have been identified: Ni5As2, Ni12−xAs8 (maucherite), and NiAs (niccolite). The first of these is homogeneous from Ni5As2 to Ni4.8A2 at room temperature, and to Ni4.6As2 above 250 °C., while the latter is homogeneous from NiAs to Ni0.95As. Contrary to expectations the stability region of the compound Ni12−xAs8 is very narrow, and occurs at Ni11As8 rather than at Ni3As2. Evidence is presented in support of Hansen's contention that this compound has an incongruent melting point. Alloys in the region corresponding to Ni4.6As2 undergo two transitions below 200 °C, one of which is martensitic and produces a metastable phase, while the other is believed to result in the formation of a new compound, as yet unidentified. The diffraction patterns are discussed in some detail.

Enhanced Performance Induced by Phase Transition of Li2FeSiO4 upon Cycling at High Temperature

2020 ◽  
Author(s):  
Titus Masese ◽  
Yuki Orikasa ◽  
Kentaro Yamamoto ◽  
Yosuke Horie ◽  
Rika Hagiwara ◽  
...  
Keyword(s):  
Phase Transition ◽  
Phase Transformation ◽  
High Temperature ◽  
High Temperatures ◽  
Room Temperature ◽  
High Energy ◽  
Temperature Cycling ◽  
High Energy Density ◽  
Slow Phase ◽  
Rate Performance

<p>Owing to its low cost, thermal stability and theoretically high capacity, Li<sub>2</sub>FeSiO<sub>4 </sub>has been a promising cathode material for high-energy-density Li-ion (Li<sup>+</sup>) battery system. However, its poor rate performance and high voltage polarisation attributed to innately slow Li<sup>+</sup> kinetics at room temperature, has fundamentally curbed its ascent into prominence. Here, the rate performance of Li<sub>2</sub>FeSiO<sub>4</sub> at high temperatures in electrolyte comprising molten salt (ionic liquid) was investigated. Subsequently, a comparison of the phase transition behaviour observed at both high-temperature and room-temperature cycling was elucidated. Our results show that remarkable rate performance with good cyclability in conjunction with low voltage polarisation is attained upon cycling of Li<sub>2</sub>FeSiO<sub>4</sub> at high temperatures, due to the faster phase transformation from unstable monoclinic structures to thermodynamically stable orthorhombic structures triggered by elevated temperature. What this study adds to the burgeoning body of research work relating to the silicates is that the initially slow phase transformation behaviour observed at room temperature can significantly be enhanced upon cycling at elevated temperatures.</p>

Atomic Interdiffusion in Au/Amorphous Ni-Nb/Semiconductor Systems

1982 ◽  
Vol 18 ◽  
Author(s):  
B. L. Doyle ◽  
P. S. Peercy ◽  
R. E. Thomas ◽  
J. H. Perepezko ◽  
J. D. Wiley
Keyword(s):  
High Temperature ◽  
Diffusion Barrier ◽  
Amorphous Metals ◽  
Temperature Range ◽  
High Temperature Electronics ◽  
Operation Temperature ◽  
The Stability

Backscattering measurements were performed to assess the stability of amorphous Ni-Nb for contacts of high temperature electronics. The interdiffusion of amorphous Ni-Nb and three semiconductors—silicon, GaAs and GaP—was measured to study the stability for primary metallization applications. Diffusion of gold with amorphous Ni-Nb and the same three semiconductors was also investigated in order to address diffusion barrier applications of amorphous metals. The results indicate that the use of amorphous Ni-Nb as a contact or a diffusion barrier could extend the useful operation temperature range for GaP devices to above 550°C.

Research on Reaction Mechanism of SiC and AlF3 in CO Atmosphere

2011 ◽  
Vol 233-235 ◽  
pp. 2610-2614
Author(s):  
Jia Ping Wang ◽  
Yong Li ◽  
Xiao Yan Zhu ◽  
Jun Bo ◽  
Jian Fang Zhang ◽  
...  
Keyword(s):  
High Temperature ◽  
Reaction Mechanism ◽  
Room Temperature ◽  
Aluminum Electrolysis ◽  
Experimental Results ◽  
Reaction Products ◽  
Operation Temperature ◽  
Electrolysis Cells ◽  
Major Reaction ◽  
Reaction Intensity

The reaction between SiC and AlF3 has been investigated in CO atmosphere at high temperature. Experimental results are shown that the reaction intensity between SiC and AlF3 is accelerated with the rise of temperature. At the temperature of 950 (aluminum electrolytic operation temperature is 935±15), the reaction intensity of SiC and AlF3 is not high and the major reaction products are SiF4 gas and Al4C3; Al4C3 occur severe hydration at room temperature which leads to the pulverization of specimens. The unexpected cells stop should try to be avoided or reduced during the usage of Si3N4-bonded SiC sidewall brick in aluminum electrolysis cells because of Al4C3 existents possibly.

Enhanced Performance Induced by Phase Transition of Li2FeSiO4 upon Cycling at High Temperature

2020 ◽  
Author(s):  
Titus Masese ◽  
Yuki Orikasa ◽  
Kentaro Yamamoto ◽  
Yosuke Horie ◽  
Rika Hagiwara ◽  
...  
Keyword(s):  
Phase Transition ◽  
Phase Transformation ◽  
High Temperature ◽  
High Temperatures ◽  
Room Temperature ◽  
High Energy ◽  
Temperature Cycling ◽  
High Energy Density ◽  
Slow Phase ◽  
Rate Performance

<p>Owing to its low cost, thermal stability and theoretically high capacity, Li<sub>2</sub>FeSiO<sub>4 </sub>has been a promising cathode material for high-energy-density Li-ion (Li<sup>+</sup>) battery system. However, its poor rate performance and high voltage polarisation attributed to innately slow Li<sup>+</sup> kinetics at room temperature, has fundamentally curbed its ascent into prominence. Here, the rate performance of Li<sub>2</sub>FeSiO<sub>4</sub> at high temperatures in electrolyte comprising molten salt (ionic liquid) was investigated. Subsequently, a comparison of the phase transition behaviour observed at both high-temperature and room-temperature cycling was elucidated. Our results show that remarkable rate performance with good cyclability in conjunction with low voltage polarisation is attained upon cycling of Li<sub>2</sub>FeSiO<sub>4</sub> at high temperatures, due to the faster phase transformation from unstable monoclinic structures to thermodynamically stable orthorhombic structures triggered by elevated temperature. What this study adds to the burgeoning body of research work relating to the silicates is that the initially slow phase transformation behaviour observed at room temperature can significantly be enhanced upon cycling at elevated temperatures.</p>

An improved goniometer head for high-temperature single-crystal X-ray diffraction

1999 ◽  
Vol 32 (4) ◽  
pp. 824-826 ◽  
Author(s):  
Patrice Delarue ◽  
Michel Jannin
Keyword(s):  
High Temperature ◽  
Data Collection ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
Charge Coupled Device ◽  
X Ray ◽  
Space Saving ◽  
The Stability ◽  
Ccd Detectors ◽  
Goniometer Head

A reliable and inexpensive goniometer head has been designed. Its stability, resulting from its compact construction, makes it very suitable for accurate measurements. Moreover, its space-saving design facilitates its application in X-ray data collection using charge-coupled device (CCD) detectors. This head has been improved for high-temperature measurements and has been tested by comparison of accurate K0.88Rb0.12TiOPO4data collected both at room temperature and at 973 K on the same crystal. The excellent structure results obtained at 973 K during the 360 h of measurements prove the stability of the goniometer head.

Beneficial Effects Induced by High Temperature Cycling in Aged Duplex Stainless Steel

2007 ◽  
Vol 345-346 ◽  
pp. 339-342 ◽  
Author(s):  
A.F. Armas ◽  
Suzanne Degallaix ◽  
Gérard Degallaix ◽  
S. Hereñú ◽  
C. Marinelli ◽  
...  
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Fatigue Life ◽  
Stainless Steels ◽  
Room Temperature ◽  
Temperature Cycling ◽  
Cyclic Behavior ◽  
Beneficial Effects ◽  
Composition Fluctuations ◽  
Strain Cycling

The cyclic behavior of type DIN 1.4460 duplex stainless steels in as-received and aged conditions was investigated at room temperature and at 500°C. At room temperature, the aged samples showed embrittlement effects such as loss of toughness and reduction of fatigue life. At 500°C, beneficial effects of the synergy between temperature and strain cycling were observed. It is proposed that at high temperature in the ferrite the strain cycling can decompose the chemical composition fluctuations, promoting a demodulation of the spinodal decomposition formed by aging.

Thermal Stress Analysis for Differential Pressure Sensors

2005 ◽  
Author(s):  
J. Albert Chiou ◽  
Steven Chen
Keyword(s):  
Thermal Stress ◽  
Thermal Stresses ◽  
Thermal Hysteresis ◽  
Pressure Sensors ◽  
Experimental Tests ◽  
Temperature Cycling ◽  
Finite Element Analyses ◽  
Sensing Element ◽  
Pressure Sensing ◽  
Temperature Environment

Pressure sensors should be capable of measuring pressure accurately and consistently without being disturbed by the temperature environment. With silicon’s better thermal material properties, silicon micormachined pressure sensors are mass-produced and widely used. However, a silicon pressure sensing element has to be packaged and protected. The thermal mismatching between the sensing element and packaging may generate stresses on the transducer of a sensing element and create thermal hysteresis and voltage shift during temperature cycling. The induced thermal stresses can easily deteriorate performance reliability. In this paper, finite element analyses and experimental tests were conducted to reduce the thermal stress and thermal hysteresis. With the glass substrate to isolate the stress from plastic housing, the thermal hysteresis can be significantly improved. The die placement and dispense pattern can be also optimized to further improve the thermal hysteresis.

scholarly journals Effect of HfO2-Based Multi-Dielectrics on Electrical Properties of Amorphous In-Ga-Zn-O Thin Film Transistors

Coatings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1381
Author(s):  
Ruozheng Wang ◽  
Qiang Wei ◽  
Jie Li ◽  
Jiao Fu ◽  
Yiwei Liu ◽  
...  
Keyword(s):  
Thin Film ◽  
Room Temperature ◽  
Electrical Characteristics ◽  
Defect States ◽  
Electrical And Optical Properties ◽  
Bias Stress ◽  
Bias Stability ◽  
The Stability ◽  
Quality Surface

We report the fabrication of bottom gate a-IGZO TFTs based on HfO2 stacked dielectrics with decent electrical characteristics and bias stability. The microscopic, electrical, and optical properties of room temperature deposited a-IGZO film with varied oxygen content were explored. In order to suppress the bulk defects in the HfO2 thin film and hence maximize the quality, surface modification of the SiNx film was investigated so as to achieve a more uniform layer. The root mean square (RMS) roughness of SiNx/HfO2/SiNx (SHS) stacked dielectrics was only 0.66 nm, which was reduced by 35% compared with HfO2 single film (1.04 nm). The basic electrical characteristics of SHS-based a-IGZO TFT were as follows: Vth is 2.4 V, μsat is 21.1 cm2 V−1 s−1, Ion/Ioff of 3.3 × 107, Ioff is 10−11 A, and SS is 0.22 V/dec. Zr-doped HfO2 could form a more stable surface, which will decrease the bulk defect states so that the stability of device can be improved. It was found that the electrical characteristics were improved after Zr doping, with a Vth of 1.4 V, Ion/Ioff of 108, μsat of 19.5 cm2 V−1 s−1, Ioff of 10−12 A, SS of 0.18 V/dec. After positive gate bias stress of 104 s, the ΔVth was decreased from 0.43 V (without Zr doping) to 0.09 V (with Zr doping), the ΔSS was decreased from 0.19 V/dec to 0.057 V/dec, respectively, which shows a meaningful impact to realize the long-term working stability of TFT devices.

scholarly journals The Study of the Effect of the Hot Box on the Stress-Strain State of the High Temperature Petrochemical Vessels

2018 ◽  
Author(s):  
Igor Laskin ◽  
Boris Volfson ◽  
Pavel Redikultsev
Keyword(s):  
Heat Transfer ◽  
Thermal Stress ◽  
High Temperature ◽  
Radiative Heat Transfer ◽  
Strain State ◽  
Thermal Stresses ◽  
Radiative Heat ◽  
Weld Zone ◽  
Thermal Gradients ◽  
State Process

The majority of studies of the heat transfer inside the hot box treats the heat transfer as a steady-state process. This paper demonstrates that this approach cannot be applied to the most dangerous cases of the cyclic thermal stress. The significant thermal gradients may occur in the skirt to shell junction of a high-temperature vessel and set up critical thermal stresses. It is a common practice to use a hot box to equalize temperatures of a shell and a skirt support. Reduction of thermal gradient results from a radiative heat transfer inside this hot box. Where a heating/cooling rate is high enough, as in coke drums, for example, the accounting of transient alters radically the distribution of a thermal stress state, and allows us to reconsider the mechanics of the fracture growth in the skirt to shell weld. This paper proves that during the cooling of coke drums some parts of the skirt support have higher temperatures than the shell, which causes tensile circumferential stresses in the weld. The intensity of the radiative heat transfer falls rapidly, when cooling a shell down to 247 °C, which leads to the increase of thermal gradients in the weld zone. This paper proposes a solution to the thermal problem in 2D, and strain-state analysis — in 3D, due to the presence of skirt slots equally spaced around skirt circumference, which increases the circumferential flexibility. The two-dimensional thermal field has been interpolated to a three-dimensional hexagonal grid for solving the thermo-strength transient problem.

Sign in / Sign up

Export Citation Format

Share Document