Thermionic Emission of Yttrium Dodecaboride Single Crystal

2019 ◽  
Vol 289 ◽  
pp. 47-52 ◽  
Author(s):  
Daniil Voronovych ◽  
Anatoliy Taran ◽  
Oksana Podshyvalova ◽  
Natalya Shitsevalova ◽  
Volodymyr Filipov ◽  
...  
Keyword(s):  
Single Crystal ◽  
Work Function ◽  
Current Density ◽  
Crystal Surface ◽  
High Vacuum ◽  
Electron Work Function ◽  
Linear Functions ◽  
Zero Field ◽  
Effective Electron ◽  
Temperature Dependences

Experimental data on thermionic current density and electron work function of YB12 (100) at T = 1218 – 1978 K in high vacuum (p < 10-4 Pa) are first introduced. Temperature dependences of the thermionic current density and effective electron work function are presented without extrapolation to the zero-field currents because of the anomalous Schottky effect. The temperature dependences of theYB12 electron work function can be described by linear functions at certain temperature intervals. Preferential boron evaporation and additional ion bombardment by the residual gases ions and evaporated boron ions results in appearance of new phases depleted of boron on the YB12 surface. As a result, an YB4 – YB6 double layer on the YB12 single crystal surface has formed. The appearance of the new boride phases, depleted of boron, on the emitting surface causes an increase of thermionic current density compared with individual YB12.

Pulsed U.V. Laser Cleaning Of GaSb Single Crystal Surface In Ultra-High-Vacuum

1989 ◽  
Author(s):  
E. J. Petit ◽  
V. M. Humblet ◽  
A. Brezini ◽  
R. Caudano ◽  
A. Gouskov ◽  
...  
Keyword(s):  
Single Crystal ◽  
Crystal Surface ◽  
High Vacuum ◽  
Laser Cleaning ◽  
Ultra High Vacuum ◽  
Single Crystal Surface

scholarly journals Исследование электростатической системы поверхности кристаллов AuNi/GaN диодов Шоттки методом зонда Кельвина атомно-силовой микроскопии

2020 ◽  
Vol 54 (3) ◽  
pp. 266
Author(s):  
Н.А. Торхов ◽  
В.А. Новиков
Keyword(s):  
Work Function ◽  
Ohmic Contacts ◽  
Crystal Surface ◽  
Contact Region ◽  
Schottky Diodes ◽  
Schottky Contact ◽  
Electron Work Function ◽  
Decisive Role ◽  
Force Microscopy ◽  
Area And Perimeter

Abstract Using atomic-force-microscopy investigations of the electrostatic system of the crystal surface of AuNi/ n – n ^+-GaN planar Schottky diodes, it is shown that the electron work function for the surface of metal Schottky contacts depends on their linear size (diameter D ). At D > 120 μm, the work function of the central contact region approaches the work function e φ_Au ≈ 5.40 eV of a continuous metallic gold film. A decrease in the diameter leads to a decrease in the work function to 5.34 eV at D = 120 μm, 5.21 eV at D = 40 μm, 5.18 eV at D = 10 μm, and 5.14 eV at D = 5 μm. The observed decrease in the work function with diameter is related to the increasing influence of the built-in periphery electrostatic field E _ l , which is determined by the area and perimeter of the Schottky contact. The fundamental differences between the thermodynamic and electrostatic systems of TiAlNiAu/ n ^+-GaN ohmic contacts, in contrast to analogous AuNi/ n -GaN Schottky systems, are indicative of the absence of a Schottky barrier in them and the decisive role of the thermionic transport of mobile carriers.

UHV Microscopy of the Reconstructed Au (001) Surface

1990 ◽  
Vol 208 ◽  
Author(s):  
D. N. Dunn ◽  
L. D. Marks ◽  
J. P. Zhang
Keyword(s):  
Single Crystal ◽  
Crystal Surface ◽  
High Vacuum ◽  
Dark Field ◽  
Ultra High Vacuum ◽  
Bulk Single Crystal ◽  
Transmission Electron ◽  
Dark Field Microscopy ◽  
Reconstructed Surface ◽  
Diffraction Patterns

ABSTRACTWe investigate the evolution of the microstructure of a reconstructed Au (001) single crystal surface using ultra high vacuum transmission electron microscopy (UHV-TEM). Bulk single crystal Au (001) surfaces were prepared via standard metallographic techniques and sputter anneal cycles. After a clean surface was obtained, the (001) surface was found to reconstruct into two nearly orthogonal domains of dimensions (5 × ∼ 20 ) along the <110> directions of the unreconstructed F.C.C. (001) surface. Transmission electron diffraction patterns (TED) and dark field microscopy are the two primary techniques used to determine the symmetry and dimensions of the reconstructed surface.

Thermionic Emission from a Niobium Single Crystal

1974 ◽  
Vol 52 (17) ◽  
pp. 1589-1593 ◽  
Author(s):  
R. P. Leblanc ◽  
B. C. Vanbrugghe ◽  
F. E. Girouard
Keyword(s):  
Single Crystal ◽  
Work Function ◽  
Surface Structure ◽  
Whisker Growth ◽  
Crystal Surface ◽  
Thermionic Emission ◽  
Etch Pits ◽  
Spherical Projection

A spherical projection diode was used to determine the Richardson constants from a niobium spherical single crystal. Work function and AR values are reported for the [110], [111], [112], [113], [116], [001], and [310] crystallographic directions. Examination of the crystal surface revealed plateau-like surface structure, thermal etch pits, and whisker growth.

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