RHEED Observation of Tin Atomic Chains Formation on Vicinal Gallium Arsenide Plane

2000 ◽  
Vol 648 ◽  
Author(s):  
Aleksey Senichkin ◽  
Aleksandr Bugaev ◽  
Vladimir Mokerov
Keyword(s):  
Gallium Arsenide ◽  
High Temperatures ◽  
Vicinal Surfaces ◽  
Atomic Chains ◽  
Diffraction Picture

AbstractIn the present work by means of measurements of RHEED intensity the research of the arrangement of tin atoms on vicinal surfaces of GaAs crystals was carried out. The orientation of crystals was close to (001). The intensity of diffracted electrons was measured in different points of the diffraction picture to reveal the arrangement of tin atoms on terraces or on edges of terraces. It was shown that tin atoms may decorate edges of terraces and thus form chains. Concentrations of tin atoms located on terraces and their edges were established. It was revealed, that tin atoms decorate edges of terraces only at rather high temperatures of a substrate.

Knoop hardness anisotropy on {001} faces of germanium and gallium arsenide

1986 ◽  
Vol 1 (1) ◽  
pp. 162-176 ◽  
Author(s):  
S. G. Roberts ◽  
P. D. Warren ◽  
P. B. Hirsch
Keyword(s):  
Gallium Arsenide ◽  
Plastic Zone ◽  
High Temperatures ◽  
Azimuthal Angle ◽  
Knoop Hardness ◽  
New Model ◽  
Hardness Anisotropy ◽  
Increasing Temperature ◽  
P Type

Knoop hardness measurements have been carried out as a function of azimuthal angle and temperature (in the range 20°–440°C) on {001} faces of n-type, p-type, and intrinsic Ge and GaAs. The degree of hardness anisotropy shown increases with increasing temperature and for Ge is undetectable below a certain temperature which depends on doping. In GaAs, asymmetry in hardness between [110] and [110] directions was found at high temperatures. A new model of hardness anisotropy has been developed, based on detailed modeling of the plastic zone. This relates the hardness to the degree of workhardening in different regions of the plastic zone. Using this model, detailed explanations are given of the hardness anisotropy behavior and of the plastic recovery around indentations.

Electrical Properties ofn-Type Gallium Arsenide at High Temperatures

1971 ◽  
Vol 10 (3) ◽  
pp. 392-394 ◽  
Author(s):  
Kenzo Akita ◽  
Hiroaki Iida ◽  
Osamu Ryuzan
Keyword(s):  
Gallium Arsenide ◽  
Electrical Properties ◽  
High Temperatures

In situ REM imaging of surface processes on ceramic bulk crystals from 300 to 1670 K in a conventional TEM

1991 ◽  
Vol 49 ◽  
pp. 660-661
Author(s):  
Z. L. Wang ◽  
J. Bentley
Keyword(s):  
High Temperatures ◽  
Image Resolution ◽  
Atomic Processes ◽  
Crystal Surfaces ◽  
Beam Radiation ◽  
Surface Areas ◽  
Transmission Electron ◽  
Reflection Electron Microscopy ◽  
Gas Reactions

Studying the behavior of surfaces at high temperatures is of great importance for understanding the properties of ceramics and associated surface-gas reactions. Atomic processes occurring on bulk crystal surfaces at high temperatures can be recorded by reflection electron microscopy (REM) in a conventional transmission electron microscope (TEM) with relatively high resolution, because REM is especially sensitive to atomic-height steps.Improved REM image resolution with a FEG: Cleaved surfaces of a-alumina (012) exhibit atomic flatness with steps of height about 5 Å, determined by reference to a screw (or near screw) dislocation with a presumed Burgers vector of b = (1/3)<012> (see Fig. 1). Steps of heights less than about 0.8 Å can be clearly resolved only with a field emission gun (FEG) (Fig. 2). The small steps are formed by the surface oscillating between the closely packed O and Al stacking layers. The bands of dark contrast (Fig. 2b) are the result of beam radiation damage to surface areas initially terminated with O ions.

Multislice calculations of RHEED patterns from vicinal Si (001)

1993 ◽  
Vol 51 ◽  
pp. 1000-1001
Author(s):  
Scott Lordi
Keyword(s):  
Misorientation Angle ◽  
Incident Angle ◽  
Incident Beam ◽  
Experimental Results ◽  
Bragg Condition ◽  
Vicinal Surfaces ◽  
Kinematic Theory ◽  
Step Edges

Vicinal Si (001) surfaces are interesting because they are good substrates for the growth of III-V semiconductors. Spots in RHEED patterns from vicinal surfaces are split due to scattering from ordered step arrays and this splitting can be used to determine the misorientation angle, using kinematic arguments. Kinematic theory is generally regarded to be inadequate for the calculation of RHEED intensities; however, only a few dynamical RHEED simulations have been attempted for vicinal surfaces. The multislice formulation of Cowley and Moodie with a recently developed edge patching method was used to calculate RHEED patterns from vicinal Si (001) surfaces. The calculated patterns are qualitatively similar to published experimental results and the positions of the split spots quantitatively agree with kinematic calculations.RHEED patterns were calculated for unreconstructed (bulk terminated) Si (001) surfaces misoriented towards [110] ,with an energy of 15 keV, at an incident angle of 36.63 mrad ([004] bragg condition), and a beam azimuth of [110] (perpendicular to the step edges) and the incident beam pointed down the step staircase.

Formation and properties of metallic atomic chains and wires

2020 ◽  
Author(s):  
Aleksei G. Syromyatnikov ◽  
Sergei V. Kolesnikov ◽  
Aleksandr M. Saletsky ◽  
Andrey L. Klavsyuk
Keyword(s):  
Atomic Chains
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