The high-frequency ESR spectra of the syntetic diamond and nanodiamonds type Ib at low temperature

The ESR absorption spectra of nonirradiated and irradiated (by electrons with an energy of 2 MeV) bulk diamond and nanodiamond powder of type Ib have been studied at a wide range of frequencies (70-20 GHz) and temperature (4.2-0 K) by ESR method. It is shown, that in the ESR spectrum of bulk diamond absorption lines of ion nickel catalyst Ni+and a paramagnetic single center of the nitrogen N0 is observed. Absorption lines of the paramagnetic centers with dangling bonds on the nanodiamond surface (surface defects) in the ESR spectra are obtained.