✦ LIBER ✦

Frequency-switched pulse sequences: Homonuclear decoupling and dilute spin NMR in solids

✍ Scribed by A. Bielecki; A.C. Kolbert; M.H. Levitt

Book ID: 103027879
Publisher: Elsevier Science
Year: 1989
Tongue: English
Weight: 547 KB
Volume: 155
Category: Article
ISSN: 0009-2614
DOI: 10.1016/0009-2614(89)87166-0

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✦ Synopsis

A new rf pulse sequence is described for the decoupling of homonuclear dipolar interactions in solid state NMR. It involves alternate 2n rotations of opposite signs about the magic-angle axis in spin space, by x rf phase shifts synchronous with rapid switching of the rf carrier frequency between opposite sides of resonance; the frequency offsets and the rf field intensity satisfy the Lee-Goldburg coherent averaging condition. Direct digital frequency synthesis ensures phase coherence. The pulse sequence has significant advantages over previous methods in the case that abundant spins are irradiated while dilute spins are observed, in an experiment measuring heteronuclear spin-spin couplings.

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