Raman and ODMR Spectroscopy of NV Centers in Nanolayers and Nanopillars of ⟨ 111⟩ Diamond after Etching with a Focused Beam of Ga Ions

The spectral characteristics of the optically detected magnetic resonance of negatively charged nitrogen–vacancy (NV ^- ) centers in synthetic diamonds and nanopillars on their surface formed by a focused Ga ^+ ion beam, when the lower spin sublevels are populated with microwave radiation, are studied. In the course of studies for emerging spin resonances at different values of the external magnetic field, both a significant decrease in the gyromagnetic ratio and a significant drop in the photoluminescence contrast are revealed for the directions of the NV ^- centers inclined to the axis of the nanopillars due to residual defects from ion etching recorded on Raman spectra in the form of peaks from amorphous carbon and graphite and the stresses they create.