Work function of W(100) field emitter modified with lutetium oxide and measured with photoemission electron microscope

2009 ◽  
Vol 27 (2) ◽  
pp. 719 ◽  
Author(s):  
Hideaki Nakane ◽  
Yusuke Nakano ◽  
Takashi Kawakubo
Keyword(s):  
Electron Microscope ◽  
Work Function ◽  
Field Emitter ◽  
Lutetium Oxide ◽  
Photoemission Electron

Surface reactions observed by photoemission electron microscopy (PEEM)

1992 ◽  
Vol 50 (1) ◽  
pp. 286-287
Author(s):  
H.H. Rotermund
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Work Function ◽  
Chemical Reactions ◽  
Reaction Diffusion ◽  
Dynamic Processes ◽  
Clean Surface ◽  
Crystal Surfaces ◽  
Single Crystal Surfaces ◽  
Photoemission Electron

Chemical reactions at a surface will in most cases show a measurable influence on the work function of the clean surface. This change of the work function δφ can be used to image the local distributions of the investigated reaction,.if one of the reacting partners is adsorbed at the surface in form of islands of sufficient size (Δ>0.2μm). These can than be visualized via a photoemission electron microscope (PEEM). Changes of φ as low as 2 meV give already a change in the total intensity of a PEEM picture. To achieve reasonable contrast for an image several 10 meV of δφ are needed. Dynamic processes as surface diffusion of CO or O on single crystal surfaces as well as reaction / diffusion fronts have been observed in real time and space.

Stable Emission Characteristics of Low Work Function Amorphous Carbon Coated Transfer Mold Nickel Field Emitter Arrays in Harsh Environment

2011 ◽  
Vol 222 ◽  
pp. 138-141
Author(s):  
Masayuki Nakamoto ◽  
Jong Hyun Moon
Keyword(s):  
Work Function ◽  
Field Emission ◽  
Amorphous Carbon ◽  
Oxygen Radical ◽  
Harsh Environments ◽  
Satellite Orbits ◽  
Emission Characteristics ◽  
Field Emitter ◽  
Radical Treatment ◽  
Field Emitter Arrays

Low work function amorphous carbon Transfer Mold field emitter arrays (a-C-FEAs) have been fabricated by combining the Transfer Mold emitter fabrication method and the emitter material coating method to realize stable vacuum nanoelectronic devices in harsh environments of aerospace. The emitter tips of a-C-FEAs are extremely sharpened to 26.7-30.7 nm of tip radii. Work function of a-C-FEAs was as low as 3.6 eV compared with those of conventional emitter materials such as carbon nanotube of 5.0 eV. Oxygen radical flux intensity of 1015 atoms/cm2•sec was used for the evaluation of field emission characteristics, whose value is 107-108 times higher than those of 107-108 atoms/cm2•sec in aerospace of satellite orbits. As the oxygen radical treatment time increased, turn-on fields of Ni-FEAs exhibited the 2.2 times degradation from 14.9 V/µm to 32.7 V/µm. Those of a-C-FEAs have been keeping almost the same value of 20.8-23.7 V/µm after oxygen radical treatment. The a-C-FEAs exhibit stable field emission characteristics in harsh environments.

Imaging and measuring the electronic properties of epitaxial graphene with a photoemission electron microscope

2022 ◽  
Vol 131 (1) ◽  
pp. 015303
Author(s):  
F. Niefind ◽  
H. G. Bell ◽  
T. Mai ◽  
A. R. Hight Walker ◽  
R. E. Elmquist ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Electronic Properties ◽  
Epitaxial Graphene ◽  
Photoemission Electron
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