Electron paramagnetic resonance of the N₂V⁻ defect in ¹⁵N-doped synthetic diamond

الأصل · EN

Nitrogen is the dominant impurity in the majority of natural and synthetic diamonds, and the family of nitrogen vacancy-type (NₙV) defects are crucial in our understanding of defect dynamics in these diamonds. A significant gap is the lack of positive identification of N₂V⁻, the dominant charge state of N₂V, in diamond that contains a significant concentration of electron donors. In this paper we employ isotopically-enriched diamond to identify the EPR spectrum associated with ¹⁵N₂V⁻ and use the derived spin Hamiltonian parameters to identify ¹⁴N₂V⁻ in a natural isotopic abundance sample. The electronic wavefunction of the N₂V⁻ ground state and previous lack of identification is discussed. The N₂V⁻ EPR spectrum intensity is shown to correlate with H2 optical absorption over an order of magnitude in concentration.