The Study of the Efficiency of Nitrogen to Nitrogen‐Vacancy (NV)‐Center Conversion in High‐Nitrogen Content Samples

The nitrogen‐vacancy color center in diamond is one of the important systems in the fast‐growing field of sensing. This color center is used in both high‐resolution and high‐sensitivity sensors. However, techniques for the quick and efficient formation of NV centers are still in the development stage. Herein, a study on the influence of the electron irradiation dose on the conversion of substitutional nitrogen into NV − centers is presented. The study is done on diamonds that are highly enriched with nitrogen (≈100 ppm), which, on one hand, should maximize the effect of irradiation, and, on other hand, be of interest for high‐sensitivity magnetometers. The maximum achieved conversion efficiency is as high as 37% ± 3.7%, with no observed saturation on the electron dose even with the simplest annealing procedure. The measurements of the corresponding dephasing time made it possible to make a theoretical estimate for the shot‐noise‐limited magnetic field sensitivity per unit volume of diamond to be roughly .