Investigation of neutron-irradiated silicon by diffuse X-ray scattering

Single crystals of silicon were irradiated with neutron doses from 2.5 x 1018 n cm-2 up to 2.5 x 1019 n cm-2 (E > 0.1 MeV). X-ray diffuse scattering from the irradiated samples was measured near the (440) reflection. A combination of the lattice parameter change, Huang scattering and Stokes-Wilson scattering yields the relative volume change per interstitial (Δupsilon/Ω)sub(I) = + 0.55 and per vacancy (Δupsilon/Ω)sub(V) = - 0.50. The average degree of agglomeration of the vacancies is Zsub(V) = 3 and is nearly dose independent in the above dose range. The size of the interstitial agglomerates Zsub(I) depends strongly on the irradiation dose and varies from 6 to 18 in the same dose range as above. (orig.)