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

verfasst von

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.

Externe Organisation(en)

Philipps-Universität Marburg

Typ

Artikel

Journal

Journal of non-crystalline solids

Band

66

Seiten

501-509

Anzahl der Seiten

9

ISSN

0022-3093

Publikationsdatum

02.08.1984

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Elektronische, optische und magnetische Materialien, Keramische und Verbundwerkstoffe, Physik der kondensierten Materie, Werkstoffchemie

Elektronische Version(en)

https://doi.org/10.1016/0022-3093(84)90373-9 (Zugang: Unbekannt)