Investigation of the recovery process in low-dose neutron-irradiated 6H-SiC by lattice parameter and FWHM of diffraction peak measurements

Abstract

Nitrogen-doped 6H-SiC single crystals irradiated with a low neutron fluence of 2.0 × 1020 n/cm2 (E > 0.1 MeV) at 200°C were investigated. To evaluate the crystalline defects induced by neutron irradiation and analyse their recovery behaviour, the specimens were isochronally annealed from room temperature to 1500°C. The lattice parameters and FWHM changes of (0006) plane diffraction peaks were recorded by X-ray diffraction. The XRD results exhibit that the FWHM was broadened and then narrowed linearly when isochronal annealed over 600°C. The lattice parameter recovery curves were analysed by the first-order model, and then the rate coefficient and activation energies at each annealing step were obtained. Based on the activation energies, the recovery process was divided into four stages and the recovery mechanism was discussed.