Spin thermodynamics is used to predict relations between various aspects of pulsed spectroscopy in the case of pure nuclear quadrupole resonance (NQR) of spins $\frac{3}{2}$: pulse response for states of quadrupolar or dipolar order, and efficiency of transfer of quadrupolar into dipolar order by a pulse pair. Experimental results are presented on the NQR resonance of ${}_{}{}^{35}{}_{}{}^{}\mathrm{Cl}$ in NaCl${\mathrm{O}}_3$ single crystals. Although there is a very satisfactory overall agreement between the observations and the predictions based on the usual assumptions underlying spin thermodynamics, experiments suggest that the choice of the quasiinvariant(s) related to the spin-spin interactions in sodium chlorate should be reconsidered.

• Received 16 June 1983

DOI:https://doi.org/10.1103/PhysRevB.29.1176