Strongly non-Arrhenius self-interstitial diffusion in vanadium
نویسندگان
چکیده
Luis A. Zepeda-Ruiz,1,2,* Jörg Rottler,1 Seungwu Han,1,† Graeme J. Ackland,3 Roberto Car,1 and David J. Srolovitz1 1Princeton Institute for the Science and Technology of Materials (PRISM), Princeton University, Princeton, New Jersey 08544, USA 2Chemistry and Materials Science Directorate, Lawrence Livermore National Laboratory, P.O. Box 808, L-371, Livermore, California 94550, USA 3School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom (Received 7 July 2004; published 31 August 2004)
منابع مشابه
Simulation of the interaction between Fe impurities and point defects in V
We report improved results of atomistic modeling of V-Fe alloys. We introduced an electronic structure embedding approach to improve the description of the point defects in first-principles calculations, by including the semicore electrons in some V atoms those near the interstitial where the semicore levels are broadened but not those further from the point defect. This enables us to combine g...
متن کاملConcentration dependence of hydrogen diffusion in clamped vanadium (0 0 1) films.
The chemical diffusion coefficient of hydrogen in a 50 nm thin film of vanadium (0 0 1) is measured as a function of concentration and temperature, well above the known phase boundaries. Arrhenius analysis of the tracer diffusion constants reveal large changes in the activation energy with concentration: from 0.10 at 0.05 in H V-1 to 0.5 eV at 0.2 in H V-1. The results are consistent with a cha...
متن کاملRoles of niobium pentoxide, vanadium pentoxide and titanium dioxide in the grain growth and sintering of uranium dioxide
Pure uo2 sinters readily at temperatures below 1600°c when non-stoichiometric oxygen introduced during the presintering treatment is available for diffusion and subsequent densification. In the absence of excess oxygen sintering occurs at temperatures above 1600°C by self-diffusion of stoichiometric oxygen in uo2 • Grain growth occurs when open porosity has been eliminated and is controlled by ...
متن کاملRelationships between atomic diffusion mechanisms and ensemble transport coefficients in crystalline polymorphs.
Ionic transport in conventional ionic solids is generally considered to proceed via independent diffusion events or "hops." This assumption leads to well-known Arrhenius expressions for transport coefficients, and is equivalent to assuming diffusion is a Poisson process. Using molecular dynamics simulations of the low-temperature B1, B3, and B4 AgI polymorphs, we have compared rates of ion hopp...
متن کاملComparison of a microstructure evolution model with experiments on irradiated vanadium
A kinetic rate theory model, which includes the formation of cascade-induced clusters (CIIC), is presented. Comparison of the model to ion irradiation data on vanadium reveals the eects of helium generation and cascade-induced interstitial and vacancy clusters on microstructure evolution. The model is based on a simpli®cation of hierarchical rate equations for the clustering of helium bubbles,...
متن کامل