Electron spin resonance of NV-=SUP=-(-)-=/SUP=--centers in synthetic fluorescent diamond microcrystals under conditions of optical spin polarization

Abstract

Electron paramagnetic resonance (EPR) spectra of synthetic diamond microcrystals with NV(-)-centers have been studied. It is shown that under the conditions of irradiation of the material with the light of a xenon lamp at low temperatures ~ 100 K, the intensities of the EPR signals corresponding to the "forbidden" (Delta ms=2) and low field allowed (Delta ms=1) transitions are amplified several times, while the EPR signals from paramagnetic nitrogen and impurity nickel in the charge state -1 practically do not change. This is due to a change in the population of levels of the ground triplet state of the NV(-)- center and the optical polarization of spins in the state ms=0 of the triplet level. Keywords: nitrogen-vacancy centers, synthetic diamond, electron paramagnetic resonance, spin polarization, luminescence.