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Author Pasturel, A. ♦ Jakse, N.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS ♦ CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY ♦ ALUMINIUM ALLOYS ♦ APPROXIMATIONS ♦ ATOMIC RADII ♦ COMPUTERIZED SIMULATION ♦ COPPER ALLOYS ♦ ENTROPY ♦ LIQUIDS ♦ MOLECULAR DYNAMICS METHOD ♦ SCALING ♦ SELF-DIFFUSION ♦ TEMPERATURE DEPENDENCE ♦ TRANSPORT THEORY ♦ TWO-BODY PROBLEM ♦ VISCOSITY
Abstract We investigate the conditions for the validity of the Stokes-Einstein relation that connects diffusivity to viscosity in melts using entropy-scaling relationships developed by Rosenfeld. Employing ab initio molecular dynamics simulations to determine transport and structural properties of liquid Al{sub 1−x}Cu{sub x} alloys (with composition x ≤ 0.4), we first show that reduced self-diffusion coefficients and viscosities, according to Rosenfeld's formulation, scale with the two-body approximation of the excess entropy except the reduced viscosity for x = 0.4. Then, we use our findings to evidence that the Stokes-Einstein relation using effective atomic radii is not valid in these alloys while its validity can be related to the temperature dependence of the partial pair-excess entropies of both components. Finally, we derive a relation between the ratio of the self-diffusivities of the components and the ratio of their pair excess entropies.
ISSN 00036951
Educational Use Research
Learning Resource Type Article
Publisher Date 2016-07-25
Publisher Place United States
Journal Applied Physics Letters
Volume Number 109
Issue Number 4


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