High-frequency pulsed ENDOR spectroscopy of the NV- centre in the commercial HPHT diamond

This work reports direct 94 GHz ENDOR spectroscopy of the N-14 nuclei in the NV- centre in single-crystal diamond. Roadmaps of ENDOR frequencies were measured and hyperfine/quadrupole interaction parameters were obtained, with A(X.Y) = -2.7 MHz, A(Z) = -2.2 MHz and P = -4.8 MHz. The sign and value of each parameter was calculated using spin Hamiltonian matrix diagonalization, first and second order perturbation theory and confirmed experimentally. Magnetic field magnitude was measured by C-13 ENDOR signal with 0.02% precision or 0.5 mT. The orientation of quadrupole, hyperfine and fine structure tensors are the same within error of experiment, g-factor is isotropic. (C) 2015 Elsevier Inc. All rights reserved.