Analytical electrostatic model of silicon conical field emitters. II. Extension to devices with focusing electrode

2001 ◽  
Vol 48 (1) ◽  
pp. 144-148 ◽  
Author(s):  
L. Dvorson ◽  
Meng Ding ◽  
A.I. Akinwande
Keyword(s):  
Electrostatic Model ◽  
Field Emitters

Analytical electrostatic model of silicon conical field emitters. I

2001 ◽  
Vol 48 (1) ◽  
pp. 134-143 ◽  
Author(s):  
L. Dvorson ◽  
Meng Ding ◽  
A.I. Akinwande
Keyword(s):  
Electrostatic Model ◽  
Field Emitters

Characteristics and Application of Temperature-Field Emitters

1975 ◽  
Vol 33 ◽  
pp. 144-145
Author(s):  
N. Tamura ◽  
T. Goto ◽  
Y. Harada
Keyword(s):  
Temperature Field ◽  
Electron Microscope ◽  
Field Emission ◽  
Resolving Power ◽  
High Brightness ◽  
Field Emitters ◽  
Emission Electron ◽  
Sufficient Stability ◽  
Scanning Electron ◽  
Illuminating System

On account of its high brightness, the field emission electron source has the advantage that it provides the conventional electron microscope with highly coherent illuminating system and that it directly improves the, resolving power of the scanning electron microscope. The present authors have reported some results obtained with a 100 kV field emission electron microscope.It has been proven, furthermore, that the tungsten emitter as a temperature field emission source can be utilized with a sufficient stability under a modest vacuum of 10-8 ~ 10-9 Torr. The present paper is concerned with an extension of our study on the characteristics of the temperature field emitters.

Design of a Field-Emission Gun for the Phillips CM20/STEM microscope

1990 ◽  
Vol 48 (2) ◽  
pp. 100-101
Author(s):  
P.M. Mul ◽  
B.J.M. Bormans ◽  
L. Schaap
Keyword(s):  
High Resolution ◽  
Field Emission ◽  
Analytical Electron Microscopy ◽  
Emission Region ◽  
Attractive Alternative ◽  
Electron Holography ◽  
Field Emitter ◽  
Field Emitters ◽  
Resolution Electron ◽  
High Resolution Tem

The first Field Emission Guns (FEG) on TEM/STEM instruments were introduced by Philips in 1977. In the past decade these EM400-series microscopes have been very successful, especially in analytical electron microscopy, where the high currents in small probes are particularly suitable. In High Resolution Electron Holography, the high coherence of the FEG has made it possible to approach atomic resolution.Most of these TEM/STEM systems are based on a cold field emitter (CFE). There are, however, a number of disadvantages to CFE’s, because of their very small emission region: the maximum current is limited (a strong disadvantage for high-resolution TEM imaging) and the emission is unstable, requiring special measures to reduce the strong FEG-induced noise. Thermal field emitters (TFE), i.e. a zirconiated field emitter source operating in the thermal or Schottky mode, have been shown to be a viable and attractive alternative to CFE’s. TFE’s have larger emission regions, providing much higher maximum currents, better stability, and reduced sensitivity to vacuum conditions as well as mechanical and electrical interferences.

MICROPROCESSOR CONTROLLED REMOLDING OF FIELD EMITTERS

1986 ◽  
Vol 47 (C7) ◽  
pp. C7-453-C7-458
Author(s):  
F. HASSELBACH ◽  
M. NICKLAUS ◽  
K. ZEUNER
Keyword(s):  
Field Emitters

Enhanced Field Emission Properties of Carbon Nanotube Based Field Emitters by Dynamic Oxidation

2013 ◽  
Vol 9 (5) ◽  
pp. 619-623 ◽  
Author(s):  
Shama Parveen ◽  
Samina Husain ◽  
Avshish Kumar ◽  
Javid Ali ◽  
Mubashshir Husain ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Field Emission ◽  
Emission Properties ◽  
Field Emission Properties ◽  
Field Emitters ◽  
Dynamic Oxidation

Nickel oxide-1D/2D carbon nanostructure hybrid as efficient field emitters

2021 ◽  
Author(s):  
Palash Chandra Maity ◽  
Narasimha Vinod Pulagara ◽  
Jagdish Arya ◽  
Gurjinder Kaur ◽  
Yusuf Khan ◽  
...  
Keyword(s):  
Nickel Oxide ◽  
Carbon Nanostructure ◽  
Field Emitters

Effect of delocalization of nonbonding electron density on the stability of the M–Ccarbene bond in main group metal-imidazol-2-ylidene complexes: a computational and structural database study

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Samuel Tetteh ◽  
Albert Ofori
Keyword(s):  
Electron Density ◽  
Lone Pair ◽  
Main Group ◽  
Binding Energies ◽  
Electrostatic Model ◽  
Group Metal ◽  
Main Group Metal ◽  
Structural Database ◽  
The Stability ◽  
Lone Pair Electrons

Abstract The M–Ccarbene bond in metal (M) complexes involving the imidazol-2-ylidene (Im) ligand has largely been described using the σ-donor only model with donation of σ electrons from the sp-hybridized orbital of the carbene carbon into vacant orbitals on the metal centre. Analyses of the M–Ccarbene bond in a series of group IA, IIA and IIIA main group metal complexes show that the M-Im interactions are mostly electrostatic with the M–Ccarbene bond distances greater than the sum of the respective covalent radii. Estimation of the binding energies of a series of metal hydride/fluoride/chloride imidazol-2-ylidene complexes revealed that the stability of the M–Ccarbene bond in these complexes is not always commensurate with the σ-only electrostatic model. Further natural bond orbital (NBO) analyses at the DFT/B3LYP level of theory revealed substantial covalency in the M–Ccarbene bond with minor delocalization of electron density from the lone pair electrons on the halide ligands into antibonding molecular orbitals on the Im ligand. Calculation of the thermodynamic stability of the M–Ccarbene bond showed that these interactions are mostly endothermic in the gas phase with reduced entropies giving an overall ΔG > 0.

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