D ec 1 99 6 Theory of self - diffusion in GaAs
نویسنده
چکیده
Ab initio molecular dynamics simulations are employed to investigate the dominant migration mechanism of the gallium vacancy in GaAs as well as to assess its free energy of formation and the rate constant of gallium self-diffusion. Our analysis suggests that the vacancy migrates by second nearest neighbour hops. The calculated self-diffusion constant is in good agreement with the experimental value obtained in 69GaAs/GaAs isotope heterostructures and at significant variance with that obtained earlier from interdiffusion experiments in GaAlAs/GaAsheterostructures.
منابع مشابه
Density-functional calculations of carbon diffusion in GaAs
Self-consistent-charge density-functional tight-binding ~SCC-DFTB! calculations have been performed to survey the potential-energy surface for a single interstitial carbon atom introduced into GaAs. The results provided a possible model for the diffusion of carbon through GaAs with an activation energy of less than 1 eV. The carbon atom moves via split-interstitial and bond-centered configurati...
متن کاملTransient enhanced intermixing of arsenic-rich nonstoichiometric AlAs/GaAs quantum wells
The superlattice intermixing of arsenic-rich nonstoichiometric AlAs/GaAs quantum wells grown at lowsubstrate temperatures around 300 °C is enhanced by several orders of magnitude relative to diffusion in stoichiometric structures grown at ordinary substrate temperatures. The transient enhanced intermixing is attributed to a supersaturated concentration of group-III vacancies grown into the crys...
متن کاملEnergetics of self-diffusion in GaAs
Atomistic thermodynamic calculations are performed in order to examine the energetic% of self-diffusion in GaAs. An energetic assessment of the activation enthalpy of the saddle-point configuration of various modes of vacancy self-diffusion indicates second-nearest-neighbor hopping to be the energetically most favorable mechanism if vacancies are available in equilibrium concentrations. An asse...
متن کامل5 D ec 1 99 7 Remark on the relation between passive scalars and diffusion backward in time Paolo Muratore - Ginanneschi
The theory of stochastic differential equations is exploited to derive the Hopf's identities for a passive scalar advected by a Gaussian drift field delta-correlated in time. The result holds true both for compressible and incompressible velocity field.
متن کامل/ 98 12 49 6 v 1 2 4 D ec 1 99 8 Field Theory and the Standard Model
The following 5 lectures are devoted to key ideas in field theory and in the Standard Model.
متن کامل