Pseudopotential theory for self-diffusion and impurity diffusion: Defect-energy calculations for fcc metals

1992 ◽  
Vol 46 (9) ◽  
pp. 5229-5236 ◽  
Author(s):  
A. Ghorai
Keyword(s):  
Impurity Diffusion ◽  
Pseudopotential Theory ◽  
Energy Calculations ◽  
Defect Energy ◽  
Fcc Metals ◽  
Self Diffusion

Tracer Impurity Diffusion in Liquid Metals: K in Na and Na in K

1973 ◽  
Vol 28 (1) ◽  
pp. 117-119
Author(s):  
T. Persson ◽  
S. J. Larsson
Keyword(s):  
Liquid Metals ◽  
Activation Energies ◽  
Impurity Diffusion ◽  
Effective Activation ◽  
Kcal Mole ◽  
Self Diffusion

The diffusivities of 42K in Na and of 24Na in K have been measured between 100 ° and 285 °C, utilizing an „infinite capillary" technique. The results are adequately described by the Arrhenius relations (in cm2/s) DK in Na = 0.46 · 10-3 exp (-1.82/RT) and DNa in K = 0.93 · 10-3 exp (-2.11/RT). The differences ΔQ in effective activation energies between impurity diffusion and self-diffusion are about -0.4 kcal/mole for Na and +0.1 kcal/mole for K. This can be satisfactorily explained by electrostatic screening arguments. The impurity diffuses slower than the host atoms in Na, faster in K.

Self-Diffusion: Self-Diffusion in FCC Metals

2002 ◽  
Vol 88 ◽  
pp. 31-39
Author(s):  
Gerhard Neumann ◽  
C. Tuijn
Keyword(s):  
Fcc Metals ◽  
Self Diffusion

Pressure and Strain Effects on Diffusion

1989 ◽  
Vol 163 ◽  
Author(s):  
A. Antonelli ◽  
J. Bernholc
Keyword(s):  
Hydrostatic Pressure ◽  
Formation Energy ◽  
Defect Formation ◽  
Nearest Neighbors ◽  
Diffusion Barriers ◽  
Impurity Diffusion ◽  
Strain Effects ◽  
Self Diffusion ◽  
Lattice Matched

AbstractWe have investigated, via parameter-free calculations, the effects of hydrostatic and nonhydrostatic strains on the energetics of defect formation and self-diffusion in silicon. The three microscopic mechanisms, vacancy, interstitial, and concerted exchange, have very similar activation enthalpies at zero pressure but exhibit different behavior with hydrostatic pressure. Our results suggest that experiments performed at different pressures can determine the relative contributions of each of these mechanisms. The calculations also show that the neutral Si vacancy has a negative relaxation volume, with the nearest neighbors of the vacancy relaxing inwards, in contrast to the Si (111) surface. Large nonhydrostatic strains, which are present in e.g. Si/GexSi1-x pseudomorphic heterostractures, substantially reduce the formation energy of the tetrahedral interstitial, but do not affect the formation energy of the vacancy. These findings suggest that, aside from being another useful tool for the investigation of self-diffusion in Si, nonhydrostatic strain may significantly affect annealing and impurity diffusion in strained heterostructures. In particular, the interstitial-assisted impurity diffusion may proceed more rapidly in Si lattice-matched to GexSi1-x, but be slowed down in GexSi1-x lattice-matched to Si. The compressed GexSi1-x layers may thus act as diffusion barriers for impurities diffusing with help of native interstitials, such as B or P.

Formulation of Impurity-Vacancy Pair Formation Energy in Fast Diffusion

2010 ◽  
Vol 305-306 ◽  
pp. 49-53
Author(s):  
Amitava Ghorai
Keyword(s):  
Diffusion Coefficient ◽  
Formation Energy ◽  
Pair Formation ◽  
The Self ◽  
Fast Diffusion ◽  
Pseudopotential Theory ◽  
Self Diffusion ◽  
Impurity Diffusion Coefficient ◽  
Vacancy Pair ◽  
Self Diffusion Coefficient

In fast diffusion, the impurity diffusion coefficient is much greater than the self-diffusion coefficient. The pair mechanism is here considered to explain fast diffusion. Formulations for the formation of the pair are based upon pseudopotential theory.

EAM study of surface self-diffusion of single adatoms of fcc metals Ni, Cu, Al, Ag, Au, Pd, and Pt

1991 ◽  
Vol 253 (1-3) ◽  
pp. 334-344 ◽  
Author(s):  
C.L. Liu ◽  
J.M. Cohen ◽  
J.B. Adams ◽  
A.F. Voter
Keyword(s):  
Fcc Metals ◽  
Self Diffusion
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