Al27Nmr Structures in Ruby under Dynamic Nuclear Polarization

Abstract

The behavior of the ${\mathrm{Al}}^{27}$ NMR structures in ruby has been investigated under dynamic nuclear polarization (the solid-state effect) achieved by applying microwave pumping power at the center of a ${\mathrm{Cr}}^{3+}$ ESR line. Experimental results were found to be qualitatively consistent with the theoretical predictions. It is demonstrated that this type of investigation enables one to determine the sign of the quadrupole coupling constant.