A b j dc b rt c c c i cons tan t i i i i i i i where

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Unformatted text preview: i )RT fD i Di i i Einstein relation Solid State Ionics Research Lab. Seoul National University Kinetics Intrinsic diffusion coefficient and self- or tracer-diffusion coefficient D* DA BA RT A DA A A A f * DB DB BB RT B DB B B f Interdiffusion coefficient ~ ~ ~ D N B D A N A DB N B D A A N A DB B Solid State Ionics Research Lab. Seoul National University Kinetics 5. Thermodynamic factor ln a i ln i i 1 ln C i ln C i (ai: the activity of i i: activity coefficient of i ) arises as a conversion factor of the driving force i to C i -For a binary, due to Gibbs-Duhem equation (only in thermodynamic local equil.), N Ad ln a A +NBd ln a B 0 NA d ln a A d ln a B d ln a A d ln a B NB 0 or dN A dN B d ln N A d ln N B A = B for a binary system Solid State Ionics Research Lab. Seoul National University Kinetics Component diffusion coefficients and self-diffusion coefficients Di* Di Bi RT i Di i i f Interdiffusion coefficient, component diffusion coefficients, and self diffusion coefficients ~ ~ ~ D N 2 D1 N1D 2 ( N 2 D1 N1D 2 ) Solid State Ionics Research Lab. Seoul National University Kinetics 6. Meaning of M M G M N A G A N B G B G M M M dG M ( G A G B )dN A RT (ln a A ln a B )dN A A B 1 dG M ln a A ln aB RT dN A d ln a A d ln aB 1 d 2 G M dN A dN A RT dN 2 A d ln a A d ln aB 1 1 1 d 2 G M 2 dN A dN B N A NB N A N B RT dN B NA NB NA NB N A N B d 2 G M : the curvature of ΔGM 2 RT dN A Solid State Ionics Research Lab. Seoul National University Kinetics - Completely mixed solution d 2 G M >0 2 dN A -Partially mixed solution d 2 G M >,<0 dN 2 A G spinodal M 0 0 0 A B d 2 G M 0 0 0 2 dN A ~ ~ Di 0 Di 0 ~ Di 0 Solid State Ionics Research Lab. Seoul National University Kinetics 7. Atomistic interpretation of Kirkendall Effect Why drift? JA DA>DB JB CB ~ C A J A DA L x ~ ~ DA DB JA L JV J LV x ~ C B J B DB L x JB JV L so that J V ( L J A L J B ) 0 Vacancies generated or annihilated to keep L JV x Solid State Ionics Research Lab. v 0 or local defect equilibrium. Seoul National...
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