Synthesis, Raman scattering, and infrared spectra of a new condensed form of GaN nanophase material

2000 ◽  
Vol 15 (2) ◽  
pp. 267-269 ◽  
Author(s):  
Y. G. Cao ◽  
X. L. Chen ◽  
Y. C. Lan ◽  
Y. P. Xu ◽  
T. Xu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Raman Scattering ◽  
Infrared Spectra ◽  
Energy Shift ◽  
High Energy ◽  
Optical Mode ◽  
Bulk Gan ◽  
Raman Spectral ◽  
Thermal Stability Of ◽  
Interface Effects

A new form of transparent condensed nanophase material of GaN was synthesized directly by ammono-thermal synthetic route. Nano-sized effects and thermal stability of that material were investigated through Raman scattering and infrared spectra. Compared with bulk GaN, we observed the Raman low-energy-shift of the phonon frequency of E2(high) and the transverse optical mode [E1(TO)], the infrared high-energy-shift of, ωT, and the variation of relative intensity IE2/E1(TO). These characteristics can be attributed to the existence of the interface effects and the vacancy of N in the GaN nanophase material. This material has a high thermal stability even at 900 °C as indicated through infrared and Raman spectral investigation of annealed samples of as-synthesized nanophase material.

INFLUENCE OF HIGH ENERGY RADIATION ON THE THERMAL STABILITY OF POLYAMIDE-6

1998 ◽  
pp. 236-251 ◽  
Author(s):  
A.I. Balabanovich ◽  
W. Schnabel ◽  
G.F. Levchik ◽  
S.V. Levchik ◽  
C.A. Wilkie
Keyword(s):  
Thermal Stability ◽  
Polyamide 6 ◽  
High Energy ◽  
High Energy Radiation ◽  
Energy Radiation ◽  
Thermal Stability Of

Deep Defects in 3C-SiC Generated by H+- and He+-Implantation or by Irradiation with High-Energy Electrons

2010 ◽  
Vol 645-648 ◽  
pp. 439-442 ◽  
Author(s):  
Michael Weidner ◽  
Lia Trapaidze ◽  
Gerhard Pensl ◽  
Sergey A. Reshanov ◽  
Adolf Schöner ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Charge State ◽  
Cross Section ◽  
Capture Cross Section ◽  
Pulse Length ◽  
High Energy ◽  
Capture Cross ◽  
Intrinsic Defects ◽  
High Energy Electrons ◽  
Thermal Stability Of

Intrinsic defects in 3C-SiC are generated by implantation of H+- and He+-ions or irra¬diation with high energy electrons. The defect parameters and the thermal stability of the observed defects are determined. The capture-cross-section of the W6-center is directly measured by variation of the filling pulse length. The charge state of the W6-center is obtained from double-correlated DLTS investigations according to the Poole-Frenkel effect.

Thermal Decomposition of Supersaturated Ti1-xAlxN Solid Solution Synthesized by High-Energy Milling

2016 ◽  
Vol 9 ◽  
pp. 82-89
Author(s):  
Maya Radune ◽  
Michael Zinigrad ◽  
David Fuks ◽  
S. Hayun ◽  
Nachum Frage
Keyword(s):  
Thermal Stability ◽  
Solid Solution ◽  
Spinodal Decomposition ◽  
Density Functional ◽  
Chemical Deposition ◽  
High Energy ◽  
Nucleation And Growth ◽  
Scanning Calorimetry ◽  
Wide Range ◽  
Thermal Stability Of

Supersaturated titanium-aluminum nitride (Ti1-xAlxN) is a very attractive material for a wide range of applications due to its high oxidation and wear resistance accompanied by high strength, hardness, thermal conductivity and thermal shock resistance. Currently, its applications are limited to coatings obtained by physical or chemical deposition. Bulk materials based on Ti1-xAlxN may be fabricated by powder metallurgy approach using powders synthesized by high-energy ball milling (HEBM), which composition corresponds to supersaturated Ti1-xAlxN solid solution. In the present study, thermal stability of the supersaturated Ti1-xAlxN solid solution was investigated. According to the quasi-binary TiN-AlN phase diagram, constructed using density functional theory (DFT) analysis, the concentration ranges, where decomposition takes place through spinodal decomposition or through nucleation and growth, were determined. Experimental study on thermal stability of solid Ti1-xAlxN solution powder was conducted by means of differential scanning calorimetry (DSC), Brunauer-Emmited-Teller (BET) and XRD. The results indicated that spinodal decomposition of Ti1-xAlxN starts at 800°C, while at temperature higher than 1300°C regular decomposition (nucleation and growth) is occur.

Raman spectral study on the thermal stability of Ni/Zr/Ni/Si and Ni/Co/Ni/Si structures

2006 ◽  
Vol 37 (9) ◽  
pp. 951-953 ◽  
Author(s):  
Jia Shao ◽  
Jianzheng Lu ◽  
Wei Huang ◽  
Yuzhi Gao ◽  
Lichun Zhang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Spectral Study ◽  
Raman Spectral ◽  
Thermal Stability Of

scholarly journals Pushing the limit of layered transition metal oxide cathodes for high-energy density rechargeable Li ion batteries

2018 ◽  
Vol 11 (5) ◽  
pp. 1271-1279 ◽  
Author(s):  
U.-H. Kim ◽  
D.-W. Jun ◽  
K.-J. Park ◽  
Q. Zhang ◽  
P. Kaghazchi ◽  
...  
Keyword(s):  
Thermal Stability ◽  
High Energy ◽  
High Energy Density ◽  
Li Ion Batteries ◽  
Two Phase ◽  
Oxide Cathodes ◽  
Li Ion ◽  
Layered Transition Metal ◽  
Thermal Stability Of ◽  
W Doping

W-doping produced the two-phase (Fm3̄m and R3̄m) structure which improved the cycling and thermal stability of the Ni-rich layered cathodes.

Thermal Stability of Amorphous Ti- Cu- Ni- Sn Prepared by Mechanical Alloying

2007 ◽  
Vol 534-536 ◽  
pp. 233-236 ◽  
Author(s):  
N.T.H. Oanh ◽  
Pyuck Pa Choi ◽  
Ji Soon Kim ◽  
Dae Hwan Kwon ◽  
Young Soon Kwon
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Mechanical Alloying ◽  
Amorphous Alloys ◽  
High Energy ◽  
Scanning Calorimetry ◽  
Thermal Stability Of

Ti-Cu-Ni-Sn quaternary amorphous alloys of Ti50Cu32Ni15Sn3, Ti50Cu25Ni20Sn5, and Ti50Cu23Ni20Sn7 composition were prepared by mechanical alloying in a planetary high-energy ballmill (AGO-2). The amorphization of all three alloys was found to set in after milling at 300rpm speed for 2h. A complete amorphization was observed for Ti50Cu32Ni15Sn3 and Ti50Cu25Ni20Sn5 after 30h and 20h of milling, respectively. Differential scanning calorimetry analyses revealed that the thermal stability increased in the order of Ti50Cu32Ni15Sn3, Ti50Cu25Ni20Sn5, and Ti50Cu23Ni20Sn7.

scholarly journals Experimental Investigation of Thermal Characteristics of Kiwira Coal Waste with Rice Husk Blends for Gasification

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Deodatus Kazawadi ◽  
Geoffrey R. John ◽  
Cecil K. King’ondu
Keyword(s):  
Activation Energy ◽  
Thermal Stability ◽  
Rice Husk ◽  
Energy Recovery ◽  
Fossil Fuels ◽  
High Energy ◽  
Coal Waste ◽  
Rice Husks ◽  
Weight Percentage ◽  
Thermal Stability Of

Eminent depletion of fossil fuels and environmental pollution are the key forces driving the implementation cofiring of fossil fuels and biomass. Cogasification as a technology is known to have advantages of low cost, high energy recovery, and environmental friendliness. The performance/efficiency of this energy recovery process substantially depends on thermal properties of the fuel. This paper presents experimental study of thermal behavior of Kiwira coal waste/rice husks blends. Compositions of 0, 20, 40, 60, 80, and 100% weight percentage rice husk were studied using thermogravimetric analyzer at the heating rate of 10 K/min to 1273 K. Specifically, degradation rate, conversion rate, and kinetic parameters have been studied. Thermal stability of coal waste was found to be higher than that of rice husks. In addition, thermal stability of coal waste/rice husk blend was found to decrease with an increase of rice husks. In contrast, both the degradation and devolatilization rates increased with the amount of rice husk. On the other hand, the activation energy dramatically reduced from 131 kJ/mol at 0% rice husks to 75 kJ/mol at 100% rice husks. The reduction of activation energy is advantageous as it can be used to design efficient performance and cost effective cogasification process.

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