Surface fractals probed by adsorbate spin-lattice relaxation dispersion

被引：16

作者：

Zavada, T ^{[1
]}

Kimmich, R ^{[1
]}

机构：

[1] Univ Ulm, Sekt Kernresonanzspektroskopie, D-89069 Ulm, Germany

来源：

PHYSICAL REVIEW E | 1999年 / 59卷 / 05期

关键词：

D O I：

10.1103/PhysRevE.59.5848

中图分类号：

O35 [流体力学]; O53 [等离子体物理学];

学科分类号：

070204 ; 080103 ; 080704 ;

摘要：

Spin-lattice relaxation of strong adsorbates confined in disordered structures such as porous silica glass is treated on the basis of a relaxation mechanism due to "reorientation mediated by translational displacements." In such a situation the low-frequency spin-lattice relaxation dispersion beyond the regime where local reorientations dominate reflects molecular dynamics as well as the surface geometry on a length scale longer than 1 nm. It is shown that the power law frequently observed for the spin-lattice relaxation dispersion in porous media can be traced back to surface fractality. The fractal properties of rough surfaces and the statistics governing surface displacements enter explicitly in the expression for the dipolar correlation function. The surface fractal dimension can thus be evaluated from the low-frequency spin-lattice relaxation dispersion accessible by field-cycling NMR relaxometry. [S1063-651X(99)12905-2].

引用

页码：5848 / 5854

页数：7

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