Oxygen and Silicon Self-Diffusion in Quartz and Silica: The Contribution of First Principles Calculations

2006 ◽  
pp. 542-553
Author(s):  
Guido Roma ◽  
Yves Limoge ◽  
Layla Martin-Samos
Keyword(s):  
First Principles ◽  
First Principles Calculations ◽  
Self Diffusion

CALCULATIONS OF SELF-DIFFUSION PROCESS AND COEFFICIENT IN ORDERED B2 AlCo

2013 ◽  
Vol 27 (19) ◽  
pp. 1341034
Author(s):  
ZHI-SHENG NONG ◽  
JING-CHUAN ZHU ◽  
YONG CAO ◽  
XIA-WEI YANG ◽  
ZHONG-HONG LAI ◽  
...  
Keyword(s):  
Diffusion Process ◽  
First Principles ◽  
Diffusion Coefficients ◽  
Density Functional ◽  
Nearest Neighbor ◽  
The Self ◽  
First Principles Calculations ◽  
Self Diffusion ◽  
Diffusion Mechanisms ◽  
Semi Empirical

The self-diffusion process in B2 type intermetallic compound AlCo has been investigated by the first-principles calculations within the frame work of density functional theory (DFT). The obtained mono-vacancy formation, migration and activation energies for four self-diffusion mechanisms, the next-nearest-neighbor (NNN) jump, [110] six-jump cycle (6JC), straight [100] 6JC and bent [100] 6JC diffusion show that the NNN jump mechanism of Co vacancy requires the lowest activation energy (Q = 6.835 eV ) in these diffusion mechanisms, which indicates that it is the main way of self-diffusion in AlCo . The electronic structure including the electron density difference on (-1 1 0) plane as well as atomic Mulliken populations were calculated, and the change of bonding behavior during the [110] 6JC process was discussed in detail. Finally, the self-diffusion coefficients of NNN jump and 6JC mechanisms for AlCo were also studied via the first-principles calculations and semi-empirical predictions, which indicates that the self-diffusion coefficients for NNN jump of Co vacancy show the highest value than the others.

Prediction of Diffusion Coefficients in Liquid and Solids

2015 ◽  
Vol 364 ◽  
pp. 182-191 ◽  
Author(s):  
William Yi Wang ◽  
Bi Cheng Zhou ◽  
Jia Jia Han ◽  
Hua Zhi Fang ◽  
Shun Li Shang ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
First Principles ◽  
Diffusion Coefficients ◽  
Tracer Diffusion ◽  
First Principles Calculations ◽  
Dominant Contribution ◽  
Creep Properties ◽  
Exchange Correlation ◽  
Self Diffusion ◽  
Tracer Diffusion Coefficients

Our activities in predicting diffusion coefficients in fcc, bcc, and hcp solid solutions using first-principles calculations and in liquid usingabinitiomolecular dynamics are reviewed. These include self-diffusion coefficients [1-4], tracer diffusion coefficients in dilute solutions [5-7], calculation of migration entropy [8], tracer diffusion coefficients in metallic and oxide liquid [9, 10], and effects of vacancy on diffusion of oxygen [11, 12]. The effects of exchange correlation functionals are examined in some cases along with charge transfer between solute and solvent elements. The dominant contribution of diffusion on the effects of Re addition on the creep properties of Ni-base superalloys is discussed [13].

First-principles calculations of self-diffusion constants in silicon

1993 ◽  
Vol 70 (16) ◽  
pp. 2435-2438 ◽  
Author(s):  
Peter E. Blöchl ◽  
Enrico Smargiassi ◽  
R. Car ◽  
D. B. Laks ◽  
W. Andreoni ◽  
...  
Keyword(s):  
First Principles ◽  
First Principles Calculations ◽  
Self Diffusion ◽  
Diffusion Constants

Atomic self-diffusion anisotropy of HCP metals from first-principles calculations

2017 ◽  
Vol 128 ◽  
pp. 236-242 ◽  
Author(s):  
Lian-Ji Zhang ◽  
Tatiana I. Spiridonova ◽  
Svetlana E. Kulkova ◽  
Rui Yang ◽  
Qing-Miao Hu
Keyword(s):  
First Principles ◽  
First Principles Calculations ◽  
Diffusion Anisotropy ◽  
Self Diffusion

Role of Atomic Size and Valence in Bonding and Diffusion at Metal Surfaces

1992 ◽  
Vol 280 ◽  
Author(s):  
Peter J. Feibelman
Keyword(s):  
Diffusion Barrier ◽  
First Principles ◽  
Metal Surfaces ◽  
Experimental Results ◽  
First Principles Calculations ◽  
Atomic Size ◽  
Self Diffusion ◽  
Chemical Concepts ◽  
And Diffusion

ABSTRACTFirst-principles calculations and corresponding experimental results underline the importance of basic chemical concepts in understanding bonding and diffusion of atoms at and on metal surfaces. Examples discussed include the outward relaxation of clean Be(0001), the separation energies of metal-adatom dimers, concerted substitutional self-diffusion on fcc(001) and (110) surfaces, and adsorption and diffusion barrier sites for adatoms near steps.

Electronic Structure and X-ray Absorption Spectra of Rutile TiO2 Using First-Principles Calculations

2014 ◽  
Vol 52 (12) ◽  
pp. 1025-1029
Author(s):  
Min-Wook Oh ◽  
Tae-Gu Kang ◽  
Byungki Ryu ◽  
Ji Eun Lee ◽  
Sung-Jae Joo ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Absorption Spectra ◽  
First Principles ◽  
First Principles Calculations ◽  
Rutile Tio2 ◽  
X Ray ◽  
X Ray Absorption

To Bend or Not to Bend, the Dilemma of Multiple Bonds

2019 ◽  
Author(s):  
Michele Pizzocchero ◽  
Matteo Bonfanti ◽  
Rocco Martinazzo
Keyword(s):  
First Principles ◽  
2D Materials ◽  
Main Group ◽  
First Principles Calculations ◽  
Group 14 ◽  
Multiple Bonds ◽  
Main Group Elements ◽  
Structural Distortions

The manuscript addresses the issue of the structural distortions occurring at multiple bonds between high main group elements, focusing on group 14. These distortions are known as trans-bending in silenes, disilenes and higher group analogues, and buckling in 2D materials likes silicene and germanene. A simple but correlated \sigma + \pi model is developed and validated with first-principles calculations, and used to explain the different behaviour of second- and higher- row elements.

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