Self-diffusion in solid lithium probed by spin-lattice relaxation of ⁸Li nuclei

authored by

P. Heitjans, A. Korblein, H. Ackermann, D. Dubbers, F. Fujara, H.-J. Stockmann

Abstract

Self-diffusion in solid Li was studied via the spin-lattice relaxation of polarised radioactive ⁸Li nuclei using their asymmetric beta -decay radiation. The diffusion-induced spin-lattice relaxation rate 1/T _1diff was measured as a function of temperature from the melting point T_m=454K down to about ¹/₂T_m and as a function of the magnetic field from 8 to 700 mT. 1/T_1diff can be explained assuming the nuclear dipole-dipole interaction alone. The data are analysed in the frame of the encounter model of correlated self-diffusion. The macroscopic self-diffusion coefficient D^SD is determined over almost seven decades. A deviation from Arrhenius behaviour at elevated temperatures is interpreted in terms of a combined monovacancy/divacancy (1V/2V) mechanism. The correlation factor obtained from D^SD and tracer self-diffusion coefficients D^T, measured by mass spectroscopy, has a temperature dependence which is consistent with the 1V/2V model. The question of the possible existence of a non-classical isotope effect cannot be settled by a comparison of the present D^SD values with those known from conventional nuclear magnetic resonance on ⁷Li.

External Organisation(s)

Philipps-Universität Marburg

Type

Article

Journal

Journal of Physics F: Metal Physics

Volume

15

Pages

41-54

No. of pages

14

ISSN

0305-4608

Publication date

1985

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

General Engineering, Physics and Astronomy (miscellaneous), Metals and Alloys

Electronic version(s)

https://doi.org/10.1088/0305-4608/15/1/009 (Access: Unknown)