Takeru Nakashima

Further study of the difference in nitrogen aggregation among (111) and (100) growth sectors of synthetic diamonds

Abstract Single nitrogen atoms in synthetic diamond crystals aggregate in pairs by heat treatment under high pressure after electron irradiations. We find that the rate constants of nitrogen aggregation in the (111) growth sectors grown by the various solvents are about ten times greater than those of the (100) growth sectors. Furthermore the rate constant of nitrogen aggregation of the same sector is almost the same value. (shown Table-1). We have considered a few reasons for this fact. It may be accurate that a form of nitrogen atoms contained in (111) growth sectors of an as-grown diamond differs from that in (100) grown sectors and that the former accelerates nitrogen aggregation. Consequently we propose one nitrogen migration and aggregation model.

Optical properties and laser action of H3 center in synthetic diamond

Color centers in diamond have a potential for opto-electronic applications. Laser action of H3 centers in natural diamond has been already reported. Our interest is focused on the possibility of laser action using synthetic diamond. A first attempt was made to produce H3 centers with high density in synthetic diamond. Optical properties of the H3 centers were investigated. Sample-dependent luminescence decay time and long lived transient absorption were observed. Laser action using the H3 centers in synthetic diamond occurred though the efficiency was as low as 0.1%.