THE NITROGEN-CONTENT OF TYPE-IB SYNTHETIC DIAMOND

The concentration of single nitrogen atoms in type lb synthetic diamond has been measured, by electron paramagnetic resonance and by inert-gas fusion, as a function of the strength of the infrared absorption produced by these centres. The two methods yield, in good agreement, values of 22-0 ± 1-1 at. p.p.m. and 20-6±l-5at.p.p.m. respectively, for an absorption coefficient of 1 cm-1 at 1130 wavenumbers. These values agree tolerably well with an earlier value of 25 at. p.p.m./cm-1 given by others, so calling into question the generally accepted data pertaining to the strength of the infrared absorption produced by the A centres, or nitrogen pairs, found in type la (natural) diamond. © 1990 Taylor & Francis Ltd.