Determination of quadrupolar spin coupling for spin 7/2 using two pulse sequences

Abstract

The response of a spin 7/2 system subject to a first-order quadrupolar interaction and excited by two in-phase pulses separated by time delay τ is calculated ignoring high frequency terms. The results obtained are valid for any ratio of the quadrupolar coupling to the amplitude of an RF pulse. It is shown here that single- and multiple-quantum coherences developed during the first pulse can be detected at the end of the second pulse. Other pulse sequences with various phase cycling are also discussed. The results are applied to ⁵¹V nuclei in a single ferroelastic crystal of BiVO₄.