NUCLEAR DOUBLE RESONANCE STUDY OF NA FIRST-ORDER QUADRUPOLE SPLITTING IN A NAF-LIF MIXED CRYSTAL

A nuclear magnetic double resonance experiment has been performed to measure the high-field first-order quadrupole splittings of Na23 nuclei located in the vicinity of Li+ substitutional impurities in a single crystal of NaF. The observed quadrupole-shifted frequency of those Na23 nuclei located at (1,0,1)-type sites [relative to the Li+ impurity at the (0,0,0) lattice site] was e2qQh=±(544±10) kHz with an asymmetry parameter η=0.65±0.05. For those Na23 nuclei at (0,0,2)-type sites, e2qQh=±(856±10) kHz with η=0. The values of eq and η thus obtained are compared with theoretical calculations. A mathematical analysis of the high-field double resonance process as it applies to rare, quadrupole-interacting nuclei is also presented. © 1969 The American Physical Society.