Solid-state NMR imaging methods. Part I: Strong field gradients
✍ Scribed by Demco, Dan E. ;Bl�mich, Bernhard
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 406 KB
- Volume
- 12
- Category
- Article
- ISSN
- 1043-7347
No coin nor oath required. For personal study only.
✦ Synopsis
¨ABSTRACT: NMR imaging has been shown to be a viable and useful approach to exploring spatial chemistry and molecular dynamics of a wide range of materials. NMR provides image contrast which is fundamentally different from that of other methods. The principles of NMR imaging and spatial information applicable to materials are reviewed, and examples of current development are given. Of fundamental importance for spatial resolution in solid-state imaging are the relationships between NMR linewidth, image resolution, signal-to-noise ratio, and measuring times. The principles of NMR with spatial resolution by frequency and phase encoding are introduced. The NMR line-broadening effect characteristic for dipolar and quadrupolar solids or quasisolids can be surpassed by strong field gradients or line-narrowing methods. Correspondingly, one class of NMR imaging methods uses stray fields, strong oscillatory gradients, or multiple-quantum coherences evolution. It is discussed in Part I. In Part II the basic principles of the second class using line-narrowing methods by magic-echoes, magic-angle sample spinning, multiple-pulse excitation, and magic-angle rotating frame techniques are presented. The possibility of recording spatially resolved spectroscopic parameters by these methods is also addressed.
📜 SIMILAR VOLUMES
Contrast is the central feature that makes NMR imaging of interest for materials applications. The principles of contrast in NMR imaging of solids are introduced and illustrated, based on the use of magnetization filters for preparation of thermodynamic nonequilibrium magnetization.
To relax the high-speed requirement imposed on the gradient system used in solid-state proton imaging, we propose two simple modifications of the magic echo imaging sequence, TREV-16TS. In the first modification, the applied gradient is inverted in the middle of the RF irradiation; the second modifi