Papers by Keyword: Ab Initio Simulation

Abstract: In this paper we firstly propose and study a microscopic model of multiple twin boundary motion using the first principles and Monte Carlo simulations in Heusler Ni-Mn-X (for example, X = Ga) alloys on real tetragonal lattice. The two variants of the low temperature martensite which divided by twin boundary are considered. The Heisenberg model for magnetic subsystem and Blume-Emery-Griffiths (BEG) one for structural subsystem with magnetostructural interaction between these subsystems are used. The influence of external magnetic field and anisotropy on the twin boundary motion is studied. It is shown that proposed model gives the picture of twin boundary motion as in experiments.

Abstract: The origin of enhanced intercalation of Li-ions into TiO2-B is being examined using first principles density functional calculations. Using advanced simulation techniques, we built a comprehensive description of Li-intercalation into TiO2-B and demonstrate that it acts as a capacitor at [Li]/[Ti] ≤ 0.5, while at higher concentrations the insertion capacity is limited by Li self-diffusion.

Abstract: We studied the atomic-level structure of a model Mg-MgH2 interface by means of the Car-Parrinello molecular dynamics method (CPMD). The interface was characterized in terms of total energy calculations, and an estimate of the work of adhesion was given, in good agreement with experimental results on similar systems. Furthermore, the interface was studied in a range of temperatures of interest for the desorption of hydrogen. We determined the diffusivity of atomic hydrogen as a function of the temperature, and give an estimate of the desorption temperature.

Abstract: The paper presents the results of experimental in-situ observations of cobalt disilicide nucleation in Co+ implanted silicon and ab initio simulations of energies of small cobalt and cobaltvacancy clusters. Based on these results, microscopic nucleation mechanisms of different types of CoSi2 precipitates are discussed.