NUCLEAR-MAGNETIC-RESONANCE OF NA-23 IN AN NAMNCL3 SINGLE-CRYSTAL

The nuclear magnetic resonance of Na-23 (I = 3/2) in an NaMnCl3 single crystal grown by the Czochralski method has been investigated by empl oying a Bruker FT NMR spectrometer. From the experimental data the qua drupole coupling constant e(2)qQ/h = 155+/-2 kHz and asymmetry paramet er eta = 0 are determined at room temperature. The principal Z axis of the EFG tenser of the Na-23, the largest component, is parallel to th e crystallographic c axis. The temperature dependence of the quadrupol e parameters is also investigated in the temperature range of 140-380 K. The quadrupole coupling constant of Na-23 is found to be linearly i ncreasing as the temperature increases.