Diffusion calculations with two atomic models in h.c.p Zr-Nb diluted alloys
| Autor: | Alejandro M. F. Rivas, Viviana P. Ramunni |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Anisotropic diffusion
Ciencias Físicas Alloy Thermodynamics DILUTED ALLOYS 02 engineering and technology engineering.material 01 natural sciences Dissociation (chemistry) Ab initio quantum chemistry methods Atomic theory 0103 physical sciences General Materials Science 010306 general physics Anisotropy Quantum Condensed matter physics Chemistry AB-INITIO CALCULATIONS 021001 nanoscience & nanotechnology Condensed Matter Physics DIFFUSION Atomic diffusion Astronomía αZr-Nb VACANCY MECHANISM engineering 0210 nano-technology CIENCIAS NATURALES Y EXACTAS |
| Popis: | In this work we perform a comparison of atomic diffusion multi-frequency models for h.c.p. lattices. Specifically, in diluted h.c.p. αZr-Nb alloy, we calculate, the tracer self- and impurity diffusion coefficients, with Ghate's eight frequencies model [1] and with the 13 frequencies model recently developed by Allnatt et al. [2]. For the latter we investigate the tight-binding limit and the 5-frequency limit of the model. Our exhaustive calculations have been performed using, for both models, classical molecular static techniques (MS), as well as, quantum ab-initio calculations within both LDA and GGA approximations. Our ab-initio calculations show that a, so called, 5-frequency model, without pairs dissociation nor anisotropy in the jump frequencies, that only needs three frequencies, is sufficient to obtain solvent and solute anisotropic diffusion coefficients that are in agreement with experimental data. Fil: Ramunni, Viviana Patricia. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Rivas, Alejandro Mariano Fidel. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina |
| Databáze: | OpenAIRE |
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