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NMR diffusion measurements in heterogeneous media using pulsed radio-frequency field gradients

✍ Scribed by J.M. Dereppe; C. Moreaux; F. Humbert

Publisher
Elsevier Science
Year
1998
Tongue
English
Weight
523 KB
Volume
21
Category
Article
ISSN
1387-1811

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✦ Synopsis

The measurement of self-diffusion coefficients D by the NMR spin echo pulsed-field gradient G technique can be corrupted for systems having a background magnetic field gradient Go. The corrupting cross-term G,G can be eliminated by the use of alternating pulsed-field gradient sequences. Measurement of D can also be performed by-a rather new technique using pulsed radio-frequency field gradients and rotary echoes. This technique is basically insensitive to background gradients and does not generate any adverse effects such as eddy currents or sample vibration. These methods have been applied to mesoporous solids and heteropolyacids.

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