Electron emission mechanism of diamond characterized by combined XPS/UPS/FES

2005 ◽  
Vol 891 ◽  
Author(s):  
Hisato Yamaguchi ◽  
Takatoshi Yamada ◽  
Bradford B. Pate ◽  
Masato Kudo ◽  
Yuji Takakuwa ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electron Emission ◽  
Anode Voltage ◽  
Negative Electron Affinity ◽  
Band Diagram ◽  
Emission Mechanism ◽  
High Chemical ◽  
Mechanical Hardness ◽  
Low Threshold ◽  
High Chemical Stability

ABSTRACTDiamond has various advantages as an electron emitter in addition to the low-threshold voltage, negative electron affinity (NEA), high thermal conductivity, high mechanical hardness, and high chemical stability. The difficulty in clarification of electron emission mechanism is preventing diamond from being used in the practical use. It is extremely difficult to identify the surface potential of the emitting diamond from conventional Emission current (I)- Anode voltage (V) characteristics. If one could measure the potential of the emitting surface, the band diagram of emitting diamond can be completed. The combined spectroscopy of XPS/UPS/FES specially built for this study, is one of the most powerful tool, which could identify the potential of the emitting surface. In this study, we have succeeded in observing the origin of field-emitted electrons using our combined XPS/UPS/FES system.

Electron Emission Mechanism of Doped CVD Diamond Characterized Using Combined XPS/UPS/FES System

2006 ◽  
Vol 956 ◽  
Author(s):  
Hisato Yamaguchi ◽  
Ichitaro Saito ◽  
Yuki Kudo ◽  
Tomoaki Masuzawa ◽  
Takatoshi Yamada ◽  
...  
Keyword(s):  
Electron Emission ◽  
Anode Voltage ◽  
Natural Diamond ◽  
Chemical Vapor ◽  
Cvd Diamond ◽  
Threshold Field ◽  
Emission Mechanism ◽  
Chemical Vapor Deposited ◽  
Low Threshold ◽  
Successful Observation

ABSTRACTElectric field of less than 5 V/μm is enough to extract electrons from diamond, whereas field of one to two orders of magnitude higher is needed to extract electrons from metal emitter tips. Despite such low-threshold field, the difficulty in clarification of electron emission mechanism is the factor preventing diamond from being used in a practical use. Quite a few numbers of possible mechanisms were proposed to better understand the origin and properties of the observed emission. Most of these mechanisms were, however, based on the conventional I (Emission current)-V (Anode voltage) characteristics. Energy distribution of the field-emitted electrons is essential in direct clarification of the mechanism. In this study, combined XPS/UPS/FES system was used to characterize the electron emission mechanism of doped chemical vapor deposited (CVD) diamond. The results indicated successful observation of the origin of field-emitted electrons from doped CVD diamond comparison with natural diamond, used as a reference.

COMPRESSIVE STRENGTH AND EXPLOSIVE CHARACTERISTICS OF POLYMER-BONDED EXPLOSIVES BASED ON HEXOGEN AND FLUOROELASTOMERS

2020 ◽  
pp. 76-83
Author(s):  
Nguyen Trung Toan
Keyword(s):  
Compressive Strength ◽  
Vinylidene Fluoride ◽  
High Energy ◽  
High Chemical ◽  
Energy Characteristics ◽  
Coating Method ◽  
Polymer Bonded Explosives ◽  
Friction Sensitivity ◽  
The Impact ◽  
High Chemical Stability

This paper describes the formulation of two polymer-bonded explosives based on RDX (hexahydro-1,3,5- trinitro-1,3,5-triazine) and fluoroelastomer binders by the water-slurry coating method. The fluoroelastomers are poly(VDF-HFP) (vinylidene fluoride-hexafluoropropene copolymer) and poly(VDF-CTFE) (vinylidene fluoride-chlorotrifluoroethylene copolymer). It has been observed that the impact sensitivity and the friction sensitivity of PBX samples were significantly lower than that of the single RDX. Results also showed that two PBX formulations have high chemical stability, high energy characteristics, and equivalent to some PBX in the world. Finally, the compressive strength of these PBX compositions was found in the range of 8-12 MPa.

Exciton-derived Electron Emission from (001) Diamondp–nJunction Diodes with Negative Electron Affinity

2008 ◽  
Vol 1 (1) ◽  
pp. 015004 ◽  
Author(s):  
Daisuke Takeuchi ◽  
Toshiharu Makino ◽  
Sung-Gi Ri ◽  
Norio Tokuda ◽  
Hiromitsu Kato ◽  
...  
Keyword(s):  
Electron Affinity ◽  
Electron Emission ◽  
Negative Electron Affinity

scholarly journals TiO2-Coated ZnO Nanowire Arrays: A Photocatalyst with Enhanced Chemical Corrosion Resistance

Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1289
Author(s):  
Lan Gao ◽  
Elyes Nefzaoui ◽  
Frédéric Marty ◽  
Mazen Erfan ◽  
Stéphane Bastide ◽  
...  
Keyword(s):  
Chemical Stability ◽  
Large Scale ◽  
Organic Dyes ◽  
Synthesis Method ◽  
Atomic Layer ◽  
Strong Acid ◽  
Tio2 Coating ◽  
High Chemical ◽  
Chemical Corrosion ◽  
High Chemical Stability

Photocatalysis is proven to be the most efficient and environmentally friendly method for the degradation of organic pollutants in water purification. To meet the requirement of large-scale water treatment, there are two important points: One is the lifetime and chemical stability of the photocatalyst material, especially in the complex and harsh aqueous conditions. The other is the ease of synthesis of such photocatalysts with specific nano-morphology. In this work, two common photocatalyst materials, zinc oxide (ZnO) and titanium dioxide (TiO2), are selected to form more sustainable photocatalysts with high chemical stability. This involves the combination of both TiO2 and ZnO in a two-step simple synthesis method. It appears advantageous to exploit the conformal deposition of atomic layer deposition (ALD) to achieve nanometer-thick TiO2 coating on ZnO nanowires (NWs) with a high aspect ratio, which are firmly anchored to a substrate and exhibit a large specific surface area. The high chemical stability of the ALD TiO2 coating has been investigated in detail and proven to be effective under both strong acid and strong alkaline aqueous solutions. In addition, photocatalysis experiments with organic dyes show that via this simple two-step synthesis method, the produced ZnO/TiO2 tandem does indeed exhibit improved chemical stability in a harsh environment, while allowing efficient photodegradation.

Synthesis of glasses with high chemical stability

1980 ◽  
Vol 37 (5) ◽  
pp. 224-227
Author(s):  
B. V. Tarasov
Keyword(s):  
Chemical Stability ◽  
High Chemical ◽  
High Chemical Stability
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