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Diffusion in the System K 2 O‐SrO‐SiO 2 : III, Interdiffusion Coefficients *
Author(s) -
VARSHNEYA A. K.,
COOPER A. R.
Publication year - 1972
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1972.tb11293.x
Subject(s) - eigenvalues and eigenvectors , diffusion , effective diffusion coefficient , composition (language) , matrix (chemical analysis) , fick's laws of diffusion , chemistry , space (punctuation) , thermodynamics , materials science , mineralogy , physics , composite material , quantum mechanics , medicine , linguistics , philosophy , magnetic resonance imaging , radiology
The matrix of interdiffusion coefficients, [ D ], was determined by measuring spatial composition distribution in couples with compositions (in wt fractions) near 0.21K 2 O‐0.17SrO‐0.62SiO 2 after they were heat‐treated for various times at 630° to 810°C. The results are consistent with the Onsager hypothesis in that [ D ] at a given temperature is independent of diffusion time and the direction (in composition space) of the diffusion couple. The eigenvectors and eigenvalues of the [ D ] matrix were determined; the diffusion paths in composition space are thus easily understood. As is consistent with intuition, the “fast” eigenvector nearly parallels the direction of constant SiO 2 concentration.