High-frequency ESR spectra of the type Ib synthetic diamond and nanodiamond at low temperatures

Abstract

The ESR absorption spectra on paramagnetic centers in the type Ib bulk diamond and nanodiamond powder were studied before and after irradiation with high energy electrons (2 MeV) for a wide range of frequencies (70–120 GHz) and temperatures (4.2–90 K). The absorption lines related to the nickel-ion growth catalyst Ni 1+ and single nitrogen paramagnetic center N0 were observed in the ESR spectrum of bulk diamond. In the nanodiamond, the absorption lines of the paramagnetic centers with dangling bonds on the surface of the nanodiamond crystallites (surface defects) and the sidelines related to the hyperfine interaction were observed in the ESR spectra.