Low-temperature nuclear spin-lattice relaxation in glasses - homogeneous and inhomogeneous averaging

authored by

H. J. Stöcmann, P. Heitjans

Abstract

A phenomenological model is presented which is able to explain both temperature and magnetic field dependences of nuclear spin-lattice relaxation rates T₁^-1 observed recently in glasses at low temperatures. The model assumes randomly distributed defect centres, typical of glasses, producing internal fluctuating fields. The only restrictive assumption is a power law for the distance dependence of the responsible interaction. In accordance with experiment, homogeneous and inhomogeneous relaxation, corresponding to exponential and non-exponential relaxation behaviour, is predicted in the cases of rapid and slow spin diffusion, respectively. Describing the fluctuating interactions by a BPP-type spectral density and assuming an Arrhenius law for the correlation time, explicit expressions for T_-1^- are obtained. It is shown that by comparison of homogeneous and inhomogeneous relaxation data information on the type of interaction and the density of defect centres can be obtained.

External Organisation(s)

Philipps-Universität Marburg

Type

Article

Journal

Journal of non-crystalline solids

Volume

66

Pages

501-509

No. of pages

9

ISSN

0022-3093

Publication date

02.08.1984

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials, Ceramics and Composites, Condensed Matter Physics, Materials Chemistry

Electronic version(s)

https://doi.org/10.1016/0022-3093(84)90373-9 (Access: Unknown)