Density Functional Based Tight Binding Study of C2 and CN Deposition On (100) Diamond Surface

2001 ◽  
Vol 675 ◽  
Author(s):  
Michael Sternberg ◽  
Peter Zapol ◽  
Thomas Frauenheim ◽  
John Carlisle ◽  
Dieter M. Gruen ◽  
...  

ABSTRACTA density-functional based tight binding method was used to study elementary steps in the growth of ultrananocrystalline (UNCD) diamond. It was shown previously that C2 dimers are the dominant growth species in hydrogen-poor argon plasmas. Recent experimental evidence shows that nitrogen addition to the plasma profoundly changes the morphology of the UNCD film. CN species are believed to play a major role. Reactions of C2 and CN molecules with reconstructed diamond (100) surfaces were studied. A single CN prefers an end-on attachment to a surface atom on the unhydrided (100) surface with its C end down. It is shown how further C2 addition to the surface leads to CN-mediated diamond growth and how the CN species remain on top of the growing diamond layer.

1995 ◽  
Vol 383 ◽  
Author(s):  
G. Jungnickel ◽  
D. Porezag ◽  
Th. Frauenheim ◽  
W. R. L. Lambrecht ◽  
B. Segall ◽  
...  

ABSTRACTThe reconstruction of the diamond {1111} surface is re-examined by means of density functional theory based tight-binding molecular dynamics. Evidence is found for competition between a graphitizing tendency leading to an unreconstructed but relaxed 1 × 1 surface and a π-bonded chain-like 2 × 1 reconstruction. The implications of the possible co-existence of these two distinct surface phases for diamond growth are discussed.


2018 ◽  
Vol 19 (4) ◽  
pp. 746-757 ◽  
Author(s):  
Chien‐Pin Chou ◽  
Aditya Wibawa Sakti ◽  
Yoshifumi Nishimura ◽  
Hiromi Nakai

2020 ◽  
Author(s):  
Hugo Souza ◽  
Antonio Chaves Neto ◽  
Francisco Sousa ◽  
Rodrigo Amorim ◽  
Alexandre Reily Rocha ◽  
...  

In this work, we investigate the effects of building block separation of Phenylalanine-Tryptophan nanotube induced by the confined water molecules on the electronic properties using density-functional theory based tight-binding method. <div><br></div>


1992 ◽  
Vol 270 ◽  
Author(s):  
Th. Frauenheim ◽  
P. Blaudeck ◽  
D. Porezag

ABSTRACTSurface properties - stability and reconstruction - of clean and hydrogenated diamond (100) have been studied by real temperature molecular dynarnic (MD) simulations using an approximate density functional (DF) theory expanding the total electronic wave function in a minimal basis of localized atomic valence electron orbitals (LCAO - ansatz). The clean surface is highly unstable against a spontaneous dimerization resulting in a 2×1 reconstruction. Atomic hydrogen in the gas phase above the top surface at all temperatures and H2 molecules approaching the center of the dimer bond at room temperature are reactive in breaking the dimer π-bonds forming a monohydrogenated surface which maintains a stable 2×1 structure but with elongated surface C-C dimer bonds remaining stable against continuing hydrogen supply. The dihydrogenated surface taking a 1×1 structure, because of steric overcrowding dynamically becomes unstable against forming a 1×1 (alternating) di-, monohydrogenated surface. As first elementary reaction processes which may be discussed in relation to diamond growth we studied the thermal adsorption of CH3 and C2H2 onto a clean 2×l reconstructed (100) diamond surface.


Nano Research ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 791-799 ◽  
Author(s):  
Diego Martinez Gutierrez ◽  
Alessandro Di Pierro ◽  
Alessandro Pecchia ◽  
Leonardo Medrano Sandonas ◽  
Rafael Gutierrez ◽  
...  

2020 ◽  
Vol 98 (5) ◽  
pp. 488-496
Author(s):  
H.J. Herrera-Suárez ◽  
A. Rubio-Ponce ◽  
D. Olguín

We studied the electronic band structure and corresponding local density of states of low-index fcc Ag surfaces (100), (110), and (111) by using the empirical tight-binding method in the framework of the Surface Green’s Function Matching formalism. The energy values for different surface and resonance states are reported and a comparison with the available experimental and theoretical data is also done.


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