The spin Hamiltonian parameters calculation of ¹⁴N and ¹⁵N in natural type I diamond

The main purpose of this work is to present the ESR spectra and calculate the spin Hamiltonian parameters of ¹⁴N and ¹⁵N impurities in natural diamond. The ESR spectra of diamond crystal were measured on ESR spectrometer operating at X-band microwave frequency. The results of ESR spectra show that the diamond has a P1 center. This center gives rise to three strong resonance absorption peaks at θ = 90°, φ = 0° due to hyperfine interaction between electron spin and nuclear spin of ¹⁴N. The ESR spectra of ¹⁵N impurity consist of two satellites at the same rotation angle (φ). The effects of isolated substitution nitrogen on carbon atom produced a symmetric distortion from T_d to C_3V symmetry. According to this symmetry, the resonance magnetic field positions of ESR spectra for the rotation angles of 0°, 90° and 180° are almost overlap. The g-factor values and spin Hamiltonian parameters of ¹⁴N and ¹⁵N are: g = 2.0019, A_⊥ = 29.73, A_|| = 40.24 and g = 2.0019, A_⊥ = -39.90, A_|| = -57.05, respectively.