NMR multiple-quantum processes in a doubly rotating frame in solids |
| |
| Affiliation: | 1. School of Biosystems and Food Engineering, University College Dublin, Belfield Dublin 4, Dublin, Ireland;2. Teagasc, Ashtown Food Research Centre, Dublin, Ireland;3. UCD School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland;1. Department of Neurobiology, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland;2. Center for Magnetic Resonance Research, University of Minnesota, 2021 6th Street SE, Minneapolis, MN 55455, USA;1. Dipartimento di Fisica e Chimica dell’Università di Palermo, Via Archirafi, 36, I-90123 Palermo, Italy;2. I.N.F.N., Sezione di Catania, Catania, Italy;3. Moscow Institute of Physics and Technology, 141700, Dolgoprudny, Institutsky lane 9, Russia;4. Department of Physics, Waseda University, Tokyo 169-8555, Japan;5. Dipartimento di Matematica ed Informatica dell’Università di Palermo, Via Archirafi, 34, I-90123 Palermo, Italy |
| |
| Abstract: | Multiple-quantum transitions between nuclear spin Zeeman levels of fluorine nuclei in a CaF2 single crystal are studied by a rotary-saturation method in NMR. The theoretical studies are performed for the system consisting of spins interacting with each other through dipole-dipole coupling. The analysis of the behavior of nuclear magnetization, the second quantization of a perturbing field, and the calculation of the nth-order timedependent perturbation are all performed in the reference frame of a doubly rotating system. We found evidence that (1) one type of single spin-n quantum transitions is taking place, but another type of two spin-n quantum transitions is not confirmed yet in this crystal; (2) the linewidths of the multiple-quantum absorptions are extremely narrow at the magic angle but do not completely vanish because of the presence of a perturbing field; (3) the effects of the energy level mixing through the dipole-dipole interactions on the multiple-quantum transitions are negligible over a wide range around the magic angle; and (4) the inhomogeneity of the RF field used to quantize the spin system in the rotating frame affects considerably the results of the rotary-saturation experiments. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
