Energetics of Surface Atomic Processes

1992 ◽  
pp. 55-65
Author(s):  
T. T. Tsong
Keyword(s):  
Atomic Processes

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.

Field ion microscope investigations of atomic processes at surfaces

1989 ◽  
Vol 47 ◽  
pp. 228-229
Author(s):  
G. L. Kellogg ◽  
P. R. Schwoebel
Keyword(s):  
Single Crystal ◽  
Crystal Surface ◽  
Linear Chain ◽  
Atom Probe ◽  
Nucleation And Growth ◽  
Single Atom ◽  
Initial Structure ◽  
Atomic Processes ◽  
Single Crystal Surfaces ◽  
Field Ion Microscope

Although no longer unique in its ability to resolve individual single atoms on surfaces, the field ion microscope remains a powerful tool for the quantitative characterization of atomic processes on single-crystal surfaces. Investigations of single-atom surface diffusion, adatom-adatom interactions, surface reconstructions, cluster nucleation and growth, and a variety of surface chemical reactions have provided new insights to the atomic nature of surfaces. Moreover, the ability to determine the chemical identity of selected atoms seen in the field ion microscope image by atom-probe mass spectroscopy has increased or even changed our understanding of solid-state-reaction processes such as ordering, clustering, precipitation and segregation in alloys. This presentation focuses on the operational principles of the field-ion microscope and atom-probe mass spectrometer and some very recent applications of the field ion microscope to the nucleation and growth of metal clusters on metal surfaces.The structure assumed by clusters of atoms on a single-crystal surface yields fundamental information on the adatom-adatom interactions important in crystal growth. It was discovered in previous investigations with the field ion microscope that, contrary to intuition, the initial structure of clusters of Pt, Pd, Ir and Ni atoms on W(110) is a linear chain oriented in the <111> direction of the substrate.

scholarly journals ASCA observations of clusters of galaxies

1996 ◽  
Vol 175 ◽  
pp. 363-366
Author(s):  
Koujun Yamashita
Keyword(s):  
High Resolution Spectroscopy ◽  
Atomic Processes ◽  
Spectral Fitting ◽  
Elemental Abundances ◽  
Hot Plasma ◽  
Emission Models ◽  
Formation And Evolution ◽  
Collisional Ionization ◽  
Intracluster Gas

X-ray emissions from clusters are most likely originated from a thin hot plasma in a collisional ionization equilibrium. The optical depth of continuum component is order of 10–3, whereas that of emission lines is around unity. Present emission models used for spectral fitting can not estimate this effect, so that the determination of elemental abundances seems to include large uncertainty. The high resolution spectroscopy with ASCA gives a clue to investigate the physical state of hot intracluster gas and a impact to reconsider the basic atomic processes. This is important issue to deeply understand the structure, formation and evolution of clusters, and the origin of intracluster gas.

Photo-induced atomic processes in vitreous chalcogenides

1993 ◽  
Vol 164-166 ◽  
pp. 1159-1164 ◽  
Author(s):  
A.V. Kolobov
Keyword(s):  
Atomic Processes

Atomic processes in bicircular fields

2016 ◽  
Vol 64 (10-11) ◽  
pp. 971-980 ◽  
Author(s):  
S. Odžak ◽  
E. Hasović ◽  
W. Becker ◽  
D. B. Milošević
Keyword(s):  
Atomic Processes

Concentration-Independent Solute Segregation in Laser Annealing of Semiconductor Crystals

1983 ◽  
Vol 23 ◽  
Author(s):  
Jun-ichi Chikawa ◽  
Fumio Sato ◽  
Tadasu Sunada
Keyword(s):  
Mixed Crystal ◽  
Laser Annealing ◽  
Solute Segregation ◽  
Atomic Processes ◽  
Segregation Coefficient ◽  
Depth Profiles ◽  
Semiconductor Crystals ◽  
Impurity Segregation ◽  
Solute Atoms ◽  
Interfacial Segregation

ABSTRACTAtomic processes at the interface in regrowth following laser induced melting were investigated by observing behavior of impurity segregation. The interfacial segregation coefficient k* was obtained from depth profiles of solute atoms redistributed by laser irradiation of uniformly doped Si, Ge, and GayAl1−yAs crystals. It was found that k*=k0 for B in Si, Ga in Ge ih the growth rate range of 1 m/s. It is concluded that rapid growth freezes a state of liquid monolayer adjacent to the interface which has the character of ideal solution from dilute to eutectic composition for dopant-silicon systems and in the entire range of composition for the mixed crystal.

Tracking atomic processes throughout the formation of heteroepitaxial interfaces

2015 ◽  
Vol 50 (6) ◽  
pp. 490-498
Author(s):  
Kurt Scheerschmidt ◽  
Oussama Moutanabbir
Keyword(s):  
Atomic Processes
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