Direct nuclear resonance detection of second-order weak quadrupole effects

This direct method of detecting anisotropic effects of the second and higher orders in NMR systems with weak nuclear quadrupole interaction with a high signal/noise ratio, characteristic of standard NMR sweep spectroscopy, is based on orientationally modulated NMR (OM NMR). Expressions are derived to describe the observed OM NMR absorption signals and the factors determining the signal shape are analyzed. The main theoretical results are supported by experiment. Attention is drawn to the possible use of the effects under consideration for NMR analyses of crystals.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 110–115, September, 1991.