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Diffusion‐Induced Quadrupole Relaxation of 27 Al Nuclei in Dilute AlTi, AlCr, AlMn, and AlCu Alloys at High Temperatures
Author(s) -
Bottyán L.,
Beke D. L.,
Tompa K.
Publication year - 1983
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.2221180241
Subject(s) - activation energy , relaxation (psychology) , impurity , arrhenius equation , diffusion , quadrupole , materials science , aluminium , intermetallic , analytical chemistry (journal) , chemistry , condensed matter physics , thermodynamics , atomic physics , alloy , metallurgy , psychology , social psychology , physics , organic chemistry , chromatography
The temperature dependence of the laboratory frame spin‐lattice relaxation time of 27 Al nuclei is measured in 5N Al and in dilute AlTi, AlCr, AlMn, and AlCu alloys at 5.7 and 9.7 MHz resonance frequencies. The relaxation in pure aluminium is found to be purely due to the conduction electrons. An excess T 1 ‐relaxation contribution is detected in all Al–3d alloys investigated above 670 K. The excess relaxation rate is proportional to the impurity content and the temperature dependence of the excess contribution is of Arrhenius‐type with an activation energy of (1.3 ± 0.3) eV for all of the investigated alloys. The relaxation contribution is found to be quadrupolar in origin and is caused by the relative diffusional jumps of solute atoms and Al atoms relatively far from the impurity.