Change of electrical and optical properties of natural type-IIa diamond under intensive fast neutron irradiation

Natural type-IIa diamond samples were neutron irradiated at a high fluence level (thermal neutron fluence of 3.7/spl middot/10/sup 19/ n/cm/sup 2/ and fast neutron fluence of 2.8/spl middot/10/sup 18/ n/cm/sup 2/). Electrical and optical properties of the unirradiated, irradiated and annealed samples were studied. The conductivity of irradiated samples was recovered to original level at temperature of 900/spl deg/C. Dramatic conductivity decreasing was observed from 700/spl deg/C. The radiation damages were removed during and after annealing, as measured by IR spectroscopy.