Microprocessor-Controlled Pulsed NQR Spectrometer for Automatic Acquisition of Zeeman Perturbed Nuclear Quadrupole Spin Echo Envelope Modulations (ZSEEM )

A simple microprocessor-controlled pulsed NQR spectrometer system has been developed with the capability to acquire Zeeman perturbed spin echo envelope modulations (ZSEEM). The CPU of the system is based on the Intel Corporation 8085 A microprocessor. The performance of the spectrometer is illustrated with the presentation of ZSEEM spectra of NaClO3 and KClO3.

Orientation Dependence of the Nuclear Quadrupole Spin-lattice Relaxation of 23Na in NaNO2

The nuclear quadrupole relaxation probability W1 of 23Na in a single crystal of NaNO2 has been studied by applying a selective 180° pulse to the centre line and monitoring the exponential approach to equilibrium of the satellites. The orientation dependence of W1 at 170 K is similar in form to that at 298 K, indicating that the lattice motions responsible for the relaxation are similar at both temperatures. Ratios of the M-tensor components obtained by fitting the W1 data have been compared with the results of various point charge calculations. It indicates that the relaxation is primarily caused by interaction with the four nearest oxygen atoms and confirms that the NO2 groups oscillate and reorient primarily about the c axis.