Pulsed Nuclear Magnetic Resonance in Rotating Solids

Abstract

Pulsed nuclear-magnetic-resonance measurements have been made on rapidly rotating solid samples. Transient induction signals were observed for ${\mathrm{P}}^{31}$ and ${\mathrm{Al}}^{27}$ nuclei in ${\mathrm{Mg}}_3$ ${\mathrm{P}}_2$, ${\mathrm{Zn}}_3$ ${\mathrm{P}}_2$, and AlP powders. A stochastic theory of relaxation is used to discuss the transverse and longitudinal spin relaxation processes. Indirect nuclear exchange appears to limit the relaxation times $T_1$ and $T_2$ at high rotation rates.