Satellite structure of DNP enhanced 13C NMR spectra in diamond

The P1 nitrogen defect centres in natural type Ia diamonds have been exploited in dynamic nuclear polarization (DNP) of the ¹³C nuclei (1.1% abundant) via the solid-effect. We have achieved sufficiently large ¹³C polarizations in some diamonds to observe weak satellite lines in the ¹³C NMR spectra by using long microwave irradiation times. A study of the dependence of the NMR spectra on the crystal orientation with respect to the applied magnetic field reveals that the satellite structure originates from the small fraction of ¹³C nuclei that are involved in nearest neighbour dipole interactions. This revised version was published online in August 2006 with corrections to the Cover Date.