Formation, evolution, and prevention of thermally induced defects on germanium and silicon upon high-temperature vacuum annealing

Characteristics of silica optical material largely depend on its thermal history. In this paper, formation of thermally induced defects in silica optical material is studied. The formation process of defect is analyzed in detail. The results show that there is an obvious difference in defect formation induced by heating treatment when the composition of silica optical material changes. Defect formation mainly displays as the produce process when the initial defects of the silica material are zero. However, defect formation expresses as the produce and annealing process when the initial defects of the silica material are not zero. The initial defect concentration can be decreased significantly when the silica material is heated in high temperature. At the same time, the new defect is also produced. These theoretic results are consistent with the previous experimental ones.

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Thermally induced defects in a polycrystalline diamond layer on a tungsten carbide substrate

Physica B Condensed Matter ◽

10.1016/j.physb.2009.09.036 ◽

2009 ◽

Vol 404 (22) ◽

pp. 4485-4488 ◽

Cited By ~ 8

Author(s):

B.N. Masina ◽

A. Forbes ◽

O.M. Ndwandwe ◽

G. Hearne ◽

B.W. Mwakikunga ◽

...

Keyword(s):

Tungsten Carbide ◽

Polycrystalline Diamond ◽

Thermally Induced ◽

Diamond Layer ◽

Induced Defects

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Xps Analysis of the Sapphire Surface as a Function of High Temperature Vacuum Annealing

MRS Proceedings ◽

10.1557/proc-159-253 ◽

1989 ◽

Vol 159 ◽

Cited By ~ 5

Author(s):

E.D. Richmond

Keyword(s):

High Temperature ◽

Binding Energy ◽

Photoelectron Spectroscopy ◽

Vacuum Annealing ◽

Xps Analysis ◽

Chemical Changes ◽

Cleaning Procedure ◽

Sapphire Surface ◽

X Ray ◽

First Time

ABSTRACTFor the first time the (1102) surface of sapphire has been investigated by X-ray photoelectron spectroscopy to ascertain chemical changes resulting from annealing in vacuum at 1300° C and 1450° C. As received substrates had a substantial surface C contaminant. For substrates that were chemically cleaned before inserting them into the MBE system no trace of carbon is detected. A residual flourine contaminant results from the cleaning procedure and is desorbed by the vacuum annealing. Spectra of annealed substrates are compared to the unannealed chemically cleaned substrates. The annealed substrates exhibit 0.4 to 0.5 eV shift to higher binding energy of the Al peak and a 0.3 eV shift to higher binding energy of the O peak. In addition, a 2% depletion of oxygen from the surface occurs.

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Thermally Induced Defects on WSe2

The Journal of Physical Chemistry C ◽

10.1021/acs.jpcc.0c04440 ◽

2020 ◽

Vol 124 (28) ◽

pp. 15337-15346 ◽

Cited By ~ 2

Author(s):

William H. Blades ◽

Nicholas J. Frady ◽

Peter M. Litwin ◽

Stephen J. McDonnell ◽

Petra Reinke

Keyword(s):

Thermally Induced ◽

Induced Defects

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Through Wall Cracking in High Temperature Rotary Cooler

Volume 3: Design and Analysis ◽

10.1115/pvp2009-77013 ◽

2009 ◽

Author(s):

James Frith ◽

Robert Frith

Keyword(s):

High Temperature ◽

Corrosion Fatigue ◽

Design Principle ◽

Extreme Temperature ◽

Fatigue Cracking ◽

Water Dissociation ◽

Thermally Induced ◽

Corrosion Fatigue Crack ◽

Root Cause ◽

High Temperature Operation

After operating for a number of years, a high temperature rotary ore cooler suffered cracking. The cracks grew through the shell wall resulting in leakage of water from the water bath into the ore. Under the extreme temperature, the risk of water dissociation into hydrogen and subsequent explosion was of substantial concern and instigated the investigation in to the root cause of the cracking which was deduced to be driven by high thermally induced stresses. The root cause for the thermally induced stressing was found to be related to a design flaw that was not immediately obvious. The investigation outcome was a recommendation to change the design to eliminate the high localized stresses which were believed to be the driving force behind the corrosion fatigue crack propagation. This paper presents the investigation approach which included advanced thermal and stress analysis and reports on the general design principle that should be adopted to avoid thermal stress induced corrosion fatigue cracking under high temperature operation.

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High Temperature Vacuum Annealing and Hydrogenation Modification of Exfoliated Graphite Nanoplatelets

Journal of Engineering ◽

10.1155/2013/638576 ◽

2013 ◽

Vol 2013 ◽

pp. 1-10 ◽

Cited By ~ 6

Author(s):

Xiaobing Li ◽

Sanjib Biswas ◽

Lawrence T. Drzal

Keyword(s):

High Temperature ◽

Functional Groups ◽

Vacuum Annealing ◽

Atmospheric Oxygen ◽

Graphite Nanoplatelets ◽

Highly Active ◽

Oxygen Functional Groups ◽

Defect Sites ◽

Capacitance Characteristics ◽

Oxygen Groups

Highly active defect sites on the edges of graphene automatically capture oxygen from air to form various oxygen groups. A two-step procedure to remove various oxygen functional groups from the defect sites of exfoliated graphene nanoplatelets (GNPs) has been developed to reduce the atomic oxygen concentration from 9.5% to 4.8%. This two-step approach involves high temperature vacuum annealing followed by hydrogenation to protect the reduced edge carbon atoms from recombining with the atmospheric oxygen. The reduced GNPs exhibit decreased surface resistance and graphitic potential-dependent capacitance characteristics compared to the complex potential-dependent capacitance characteristics exhibited by the unreduced GNPs as a result of the removal of the oxygen functional groups present primarily at the edges. These reduced GNPs also exhibit high electrochemical cyclic stability for electrochemical energy storage applications.

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