The effect of structure development in electron-irradiated type Ia diamond

A type la diamond crystal with a nitrogen impurity in different forms was 3 .5 MeV electron-irradiated with successively increasing doses 5 x 10(16), 2 x 10(17), 4 x 10(17), 2 x 10(18) e/cm(2) and examined after each dose by p ositron annihilation, EPR and optical spectroscopy in visible and IR region s. After irradiation with highest dose a development of the defective struc ture of the crystal was revealed. A detail description of the phenomenon, d ata of EPR and optical measurements for different irradiation doses are giv en. The first results of cathodoluminescence studies of the as-developed st ructure are presented. Possible models of defects responsible for main line s in CL spectra are listed. (C) 1999 Kluwer Academic Publishers.