Sulfur layer formation on GaAs(100) by thermal and photochemical H2S dissociation

1995 ◽  
Vol 13 (4) ◽  
pp. 1837-1846 ◽  
Author(s):  
Matthew G. Nooney ◽  
Vladimir Liberman ◽  
Richard M. Martin
Keyword(s):  
Author(s):  
Chuxin Zhou ◽  
L. W. Hobbs

One of the major purposes in the present work is to study the high temperature sulfidation properties of Nb in severe sulfidizing environments. Kinetically, the sulfidation rate of Nb is satisfactorily slow, but the microstructures and non-stoichiometry of Nb1+αS2 challenge conventional oxidation/sulfidation theory and defect models of non-stoichiometric compounds. This challenge reflects our limited knowledge of the dependence of kinetics and atomic migration processes in solid state materials on their defect structures.Figure 1 shows a high resolution image of a platelet from the middle portion of the Nb1+αS2 scale. A thin lamellar heterogeneity (about 5nm) is observed. From X-ray diffraction results, we have shown that Nb1+αS2 scale is principally rhombohedral structure, but 2H-NbS2 can result locally due to stacking faults, because the only difference between these 2H and 3R phases is variation in the stacking sequence along the c axis. Following an ABC notation, we use capital letters A, B and C to represent the sulfur layer, and lower case letters a, b and c to refer to Nb layers. For example, the stacking sequence of 2H phase is AbACbCA, which is a ∼12Å period along the c axis; the stacking sequence of 3R phase is AbABcBCaCA to form an ∼18Å period along the c axis. Intergrowth of these two phases can take place at stacking faults or by a shear in the basal plane normal to the c axis.


1990 ◽  
Vol 87 ◽  
pp. 1597-1607 ◽  
Author(s):  
L Benedetti ◽  
M Borsari ◽  
C Fontanesi ◽  
G Battistuzzi Gavioli

2020 ◽  
Author(s):  
◽  
Linas Sinkevičius
Keyword(s):  

Investigation of polypyrrole layer formation peculiarities and formation of uric acid molecular imprints


Author(s):  
Dmitriy Parshin

The article gives an example of controlling the stress state parameters of additively manufactured products. The study was carried out on the basis of a developed non-classical mechanical model of the process of layer-by-layer formation of a coating of arbitrary thickness on a cylindrical substrate. The model is based on modern concepts of the mechanics of continuously growing bodies and allows one to obtain fairly simple analytical dependencies. On the basis of the latter, the problem of technological control of the evolution of contact pressure at the substrate – coating interface is solved in the article. A number of practically significant conclusions have been made.


2019 ◽  
Vol 14 (3) ◽  
Author(s):  
Saravanan S ◽  
Murugan G

This study addresses the effect of process parameters viz., loading ratio (mass of explosive/mass of flyer plate) and preset angle on dynamic bend angle, collision velocity and flyer plate velocity in dissimilar explosive cladding. In addition, the variation in interfacial microstructure and mechanical strength of aluminium 5052-stainless steel 304 explosive clads is reported. The interface exhibits a characteristic undulating interface with a continuous molten layer formation. The interfacial amplitude increases with the loading ratio and preset angle. Maximum hardness is observed at regions closer to the interface


1988 ◽  
Vol 24 (7) ◽  
pp. 381 ◽  
Author(s):  
H.N. Kheirallah ◽  
M.R.M. Rizk
Keyword(s):  

Author(s):  
Libo Wang ◽  
Martin Sharp ◽  
Benoit Rivard ◽  
Konrad Steffen

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