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Analysis of tracer and nuclear magnetic resonance measurements of self‐diffusion in aluminium
Author(s) -
Seeger A.,
Wolf D.,
Mehrer H.
Publication year - 1971
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2220480205
Subject(s) - self diffusion , diffusion , aluminium , tracer , activation energy , radioactive tracer , chemistry , volume (thermodynamics) , effective diffusion coefficient , analytical chemistry (journal) , atomic physics , nuclear magnetic resonance , thermodynamics , nuclear physics , magnetic resonance imaging , physics , medicine , self service , organic chemistry , radiology , marketing , chromatography , business
The various nuclear magnetic resonance techniques used for determining self‐diffusion coefficients and activation energies in aluminium are evaluated critically. The data considered most reliable are analyzed together with the Al 26 ‐tracer measurements of self‐diffusion. From the temperature and the pressure dependence of the self‐diffusion coefficients it is deduced that at high temperatures divacancies contribute appreciably to self‐diffusion in aluminium and that the self‐diffusion activation energy for a monovacancy mechanism is Q 1 E 1V F+ E 1V M= 1.28 eV. With the help of measurements on the equilibrium concentration of vacant sites Q 1 is subdivided into the formation energy E 1V F= 0.66 eV and the migration energy E 1V M= 0.63 eV. The difference between migration and binding energies of divacancies is found to be E 2V M E 2V B= 0.28 eV. It is shown that the ratio of the self‐diffusion activation volume for monovscancies to the atomic volume is smaller than unity and about equal to 0.9.