NMR Imaging Using Second Order Quadrupole Broadened Resonances

Theoretical and experimental results for NMR imaging measurements of powdered materials using the + to − transition of -integerspin nuclei in the presence of a very large second-order electric quadrupolar broadening are presented. An “effective spin-” formalism is developed to account for additional effects due to the presence of quadrupolar interactions comparable in size to the Zeeman interaction. A large (7.9 mT/cm-A, with a maximum current of ≈20 A), rapid (≈30 μs) pulsed linear gradient field is used with echoes and phase encoding techniques to obtain images in the limit γH₁is much narrower than the NMR linewidth. A one-dimensional projection of the second-order quadrupolar perturbed, 4-MHz-wide, + ↔ − transition for⁶³Cu in Cu₂O powder is presented as an example. An experimental one-dimensional projection of a sample containing Cu₂O and YBa₂Cu₃O_6.7is also presented.