Electron spin resonance in the study of diamond

Abstract

The role of electron spin resonance in the study of both natural and synthetic diamond is reviewed in this article. A brief survey of the physical significance of the constants in the spin Hamiltonian, as well as experimental technique, is given. The review then deals in some detail with the various nitrogen centres found in diamond, treating exchange-interaction, Jahn-Teller and relaxation effects associated with these centres. Acceptor impurities and transition-ion impurities are briefly discussed. The rest of the review is then devoted to centres created by irradiation, subsequent heat treatment, mechanical deformation and ion implantation. The spin Hamiltonian parameters of these centres are tabled and the results are discussed within the framework of the defect molecule approach. I n conclusion, the correlation between optical effects and the ESR measurements in the case of four defect centres are discussed in some detail as this seems to be a powerful method of testing the various models suggested for the observed defects. It is hoped that the tables given of the observed centres found in diamond up to the present will be useful to researchers in this field.

Optically detected cross-relaxation spectroscopy of electron spins in diamond

“…This indicates that we may have observed other defect centres in diamond. The unassigned fine features can be used to identify these additional centres by comparing with the unique hyperfine structures of known defect centres that are commonly found in diamond 24 . We find that the remaining fine features are most consistent with transitions of the NV 0 centre in the spin-3/2 4 A 2 excited state [25][26][27] (purple lines on top of each spectrum in (Figs 2b and 3b).…”

Incorporation of Large Impurity Atoms into the Diamond Crystal Lattice: EPR of Split-Vacancy Defects in Diamond

“…The NV 0 and NV − centers have zero-phonon lines at 575 and 637 nm. The NV − center is paramagnetic, and has the EPR spectrum fitted with S = 1, g = 2.0028, D = 103 mT, A( 14 N) = 0.08 mT, A( 13 C) || = 7.31 mT, A( 13 C) ⊥ = 4.40 mT [49].…”

All-Optical Thermometry and Thermal Properties of the Optically Detected Spin Resonances of the NV– Center in Nanodiamond

“…∼ 2.87 GHz (room-temperature) due mainly to electron spin-spin interaction. 35 Under crystal strain that distorts the C 3v symmetry of the center, the m s = ±1 sub-levels are mixed and their degeneracy is lifted. 36 41 and is consequently important to this work.…”