scholarly journals Oxygen self-diffusion mechanisms in monoclinic ZrO2 revealed and quantified by density functional theory, random walk analysis, and kinetic Monte Carlo calculations

2018 ◽  
Vol 97 (2) ◽  
Author(s):  
Jing Yang ◽  
Mostafa Youssef ◽  
Bilge Yildiz
Keyword(s):  
Density Functional Theory ◽  
Monte Carlo ◽  
Density Functional ◽  
Kinetic Monte Carlo ◽  
Monoclinic Zro2 ◽  
Functional Theory ◽  
Self Diffusion ◽  
Monte Carlo Calculations ◽  
Diffusion Mechanisms ◽  
Random Walk Analysis

Diffusion in Ni-Based Single Crystal Superalloys with Density Functional Theory and Kinetic Monte Carlo Method

2016 ◽  
Vol 20 (3) ◽  
pp. 603-618 ◽  
Author(s):  
Min Sun ◽  
Zi Li ◽  
Guo-Zhen Zhu ◽  
Wen-Qing Liu ◽  
Shao-Hua Liu ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Monte Carlo ◽  
Transition Rate ◽  
Density Functional ◽  
Diffusion Theory ◽  
Kinetic Monte Carlo ◽  
Functional Theory ◽  
Atom Diffusion ◽  
Time Stepping ◽  
Phase Intermetallic

AbstractIn the paper, we focus on atom diffusion behavior in Ni-based superalloys, which have important applications in the aero-industry. Specifically, the expressions of the key physical parameter – transition rate (jump rate) in the diffusion can be given from the diffusion theory in solids and the kinetic Monte Carlo (KMC) method, respectively. The transition rate controls the diffusion process and is directly related to the energy of vacancy formation and the energy of migration of atom from density functional theory (DFT). Moreover, from the KMC calculations, the diffusion coefficients for Ni and Al atoms in the γ phase (Ni matrix) and the γʹ phase (intermetallic compound Ni3Al) of the superalloy have been obtained. We propose a strategy of time stepping to deal with the multi-time scale issues. In addition, the influence of temperature and Al concentration on diffusion in dilute alloys is also reported.

Mechanisms of Diffusion and Dissociation of E-Centers in Silicon

2005 ◽  
Vol 237-240 ◽  
pp. 1129-1134
Author(s):  
Mariya G. Ganchenkova ◽  
V.A. Borodin ◽  
Risto M. Nieminen
Keyword(s):  
Density Functional Theory ◽  
Monte Carlo ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Density Functional ◽  
Kinetic Monte Carlo ◽  
Binding Energies ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Charge States

In this paper we discuss possible mechanisms of PV annealing in Si. Our approach includes a combination of density functional theory and lattice kinetic Monte-Carlo (LKMC) simulations. The density functional theory is used to find the binding energies and jump barriers for P-V pair at different separations (from one to three interatomic bonds between complex constituents) and in different charge states. The mobility of the complex is simulated by LKMC with event probabilities calculated based on the energies from ab-initio calculations. .

scholarly journals H2 Thermal Desorption Spectra on Pt(111): A Density Functional Theory and Kinetic Monte Carlo Simulation Study

Catalysts ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 450 ◽  
Author(s):  
Caoming Yu ◽  
Fang Wang ◽  
Yunlei Zhang ◽  
Leihong Zhao ◽  
Botao Teng ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Monte Carlo ◽  
Density Functional ◽  
Dft Calculation ◽  
Kinetic Monte Carlo ◽  
Face Centered Cubic ◽  
Monte Carlo Simulation Study ◽  
Functional Theory ◽  
Hydrogenation Catalysts ◽  
Two Peaks

Theoretical investigation of the static and kinetic behaviors of H and H2 on metal surface plays a key role in the development of hydrogenation catalysts and new materials with high H2 storage capacity. Based on the density functional theory (DFT) calculation of H and H2 adsorption on Pt(111), H(a) adatom strongly interacts with surface Pt; while H2 weakly adsorbs on Pt(111). H(a) adatoms stably occupy the face-centered cubic sites on Pt(111) which agrees with the experimental LERS observations. By using kinetic Monte Carlo (kMC) simulation, the qualitative effects of the kinetic parameters on the H2 TDS spectra indicate that the H2 desorption peaks shift to the low temperature with increasing pre-exponential factor and decreasing desorption barrier. Simultaneously, the desorption peaks shift downwards and broaden to two peaks with the increase of the lateral interaction energy among H(a) adatoms. Using the kMC simulation based on DFT calculation, the predicted H2 TDS spectra are well consistent with the experimental ones. It unanimously proves that the two peaks of TDS spectra are derived from the lateral interactions among H(a). This work provides the intrinsic kinetics of H(a) and H2 on Pt(111) at an atomic level, and gives insight into the development of hydrogenation catalysts.

Sign in / Sign up

Export Citation Format

Share Document