Self-Diffusion Coefficient of fcc Mg: First-Principles Calculations and Semi-Empirical Predictions

Zhao, Dongdong; Kong, Yi; Wang, Ai‐Jun; Zhou, Lu; Cui, Shuzhen; Yuan, Xin; Zhang, Lijun; Du, Yong

doi:10.1007/s11669-011-9854-5

Cited by 13 publications

(3 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The stability of a fault layer is dependent on both the formation energy and especially corresponding diffusion energy of the cluster. Atomic clustering processes have been intensively studied for materials with cubic structures using first principles density function theory 25 – 29 , atomistic simulations with empirical interatomic potentials 30 – 35 , and experiments coupling with theoretical interpretation 36 , 37 . A few studies were done for hexagonal metals.…”

Section: Introductionmentioning

confidence: 99%

Clustering on Magnesium Surfaces – Formation and Diffusion Energies

Chu

Huang

Wang

2017

Sci Rep

View full text Add to dashboard Cite

The formation and diffusion energies of atomic clusters on Mg surfaces determine the surface roughness and formation of faulted structure, which in turn affect the mechanical deformation of Mg. This paper reports first principles density function theory (DFT) based quantum mechanics calculation results of atomic clustering on the low energy surfaces {0001} and {1011}. In parallel, molecular statics calculations serve to test the validity of two interatomic potentials and to extend the scope of the DFT studies. On a {0001} surface, a compact cluster consisting of few than three atoms energetically prefers a facecentered-cubic stacking, to serve as a nucleus of stacking fault. On a {1011}, clusters of any size always prefer hexagonal-close-packed stacking. Adatom diffusion on surface {1011} is high anisotropic while isotropic on surface (0001). Three-dimensional Ehrlich-Schwoebel barriers converge as the step height is three atomic layers or thicker. Adatom diffusion along steps is via hopping mechanism, and that down steps is via exchange mechanism.Hexagonal metals in a bulk form are widely used in nuclear engineering 1 and transportation industry (magnesium and magnesium alloys are the lightest structural materials) 2 . Mg and Mg alloys exhibit low strength and poor deformability because of the easy twinning. Nanometer-sized hexagonal materials show significantly high strength, 5 to 10 times of the bulk strength 3, 4 . However, deformation twin quickly propagates across the sample once it occurs, corresponding to the burst of plastic deformation 5 . Planar defects such as twin boundaries, stacking faults, and interphase interfaces can impede the motion and propagation of dislocations and twins, thus strengthening materials [6][7][8][9][10] . To realize planar defects in Mg and Mg alloys, it is essential to understand atomic clustering processes during material processing (synthesizing and aging). For example, alloying with appropriate solutes alloying is very promising in tailoring mechanical properties of Mg alloys 11 . Shin and Wolverton 12 calculated solute-vacancy binding in Mg alloys using principles density function theory, and Ganeshan et al. performed first principles density function theory (DFT) calculations of self-diffusion in hcp Mg 13 . Understanding of solute clustering processes in Mg alloys has provided insight in modifying the dispersion and morphology of precipitates.Apart from clustering processes in the bulk Mg, planar defects in nanostructured Mg and Mg alloys can also be introduced during synthesizing, such as sputtering via physical vapor deposition techniques [14][15][16][17][18][19][20] . Atomic clustering on surfaces during a growth process of thin films or nanostructures dictates the structure and their mechanical properties. The clustering processes depend on formation and diffusion energies of adatom or atomic clusters. If the formation energy of an adatom or an atomic cluster in a fault stacking is lower than in a normal stacking, stacking faults may form. In addition, the diffusio...

show abstract

Section: Introductionmentioning

confidence: 99%

Clustering on Magnesium Surfaces – Formation and Diffusion Energies

Chu

Huang

Wang

2017

Sci Rep

View full text Add to dashboard Cite

show abstract

“…Refs. [3,4,[15][16][17]20,21]), contributions of phonon and/or electron excitations to the free migration energy were considered. Also in recent DFT studies on the diffusion of foreign atoms or impurities by the interstitial, the vacancy or the dumbbell mechanism (cf.…”

Section: Introductionmentioning

confidence: 99%

Influence of phonon and electron excitations on the free energy of defect clusters in solids: A first-principles study

Posselt

Murali

Schiwarth

2017

Computational Materials Science

View full text Add to dashboard Cite

show abstract

“…Moreover, diffusion coefficients in liquid phase and meta-stable phases are very limited in the literature due to the rigorous experimental conditions. Recent first-principles calculations demonstrated its promising potential to predict such diffusivities [9].…”

Section: Introductionmentioning

confidence: 99%

Atomic mobilities and diffusivities in Al alloys

Zhang

Cui

et al. 2011

Sci. China Technol. Sci.

Self Cite

View full text Add to dashboard Cite

Knowledge of diffusivity is a prerequisite for understanding many scientific and technological disciplines. In this paper, firstly major experimental methods, which are employed to provide various diffusivity data, are briefly described. Secondly, the fundamentals of various computational methods, including first-principles method, embedded atomic method/molecular dynamic simulation, semi-empirical approaches, and phenomenological DICTRA technique, are demonstrated. Diffusion models recently developed for order/disorder transitions and stoichiometric compounds are also briefly depicted. Thirdly, a newly established diffusivity database for liquid, fcc_A1, L1 2 , bcc_A2, bcc_B2, and intermetallic phases in the multicomponent Al alloys is presented via a few case studies in binary, ternary and quaternary systems. And the integration of various computational techniques and experimental methods is highlighted. The reliability of this diffusivity database is validated by comparing the calculated and measured concentration profiles, diffusion paths, and Kirkendall shifts in various binary, ternary and quaternary diffusion couples. Next, the established diffusivity databases along with thermodynamic and other thermo-physical properties are utilized to simulate the microstructural evolution for Al alloys during solidification, interdiffusion and precipitation. A special discussion is presented on the phase-field simulation of interdiffusion microstructures in a series of Ni-Al diffusion couples composed of γ, γ', and β phases under the effects of both coherent strain and external compressive force. Future orientations in the establishment of next generation of diffusivity database are finally addressed.

show abstract

Self-Diffusion Coefficient of fcc Mg: First-Principles Calculations and Semi-Empirical Predictions

Cited by 13 publications

References 39 publications

Clustering on Magnesium Surfaces – Formation and Diffusion Energies

Clustering on Magnesium Surfaces – Formation and Diffusion Energies

Influence of phonon and electron excitations on the free energy of defect clusters in solids: A first-principles study

Atomic mobilities and diffusivities in Al alloys

Contact Info

Product

Resources

About