The Study Of Properties Of Heavy-dose Neutron-irradiated Single Crystal Material

Single crystal materials under extreme condition （high dose of neutron irradiation）are studied in this paper. The morphology, electrical properties and optical propertiesof the materials are analyzed, which establishes a base for researching and developingnew materials under extreme condition.In this paper, SiC was irradiated to a total neutron dose of1.67×1020n/m2andAl₂O₃was irradiated to a total neutron dose of5.74×10¹⁸n/cm². Un-irradiated andirradiated samples and the samples annealed after irradiation were detected andanalyzed by X-ray diffraction（XRD）， Scanning Electron Microscope（SEM），Photoluminescence spectrum（PL） and Raman spectroscopy（RS）. The changes ofcharacteristics and the recovery behavior of irradiated samples are observed andanalyzed. Through the summarizing experimental data, the following mainconclusions are got：（1）Resistivity of SiC in the high-dose neutron irradiation has greatly improved andelectrical performance is severely degraded. In the subsequent annealing process, theresistivity distribution is becoming well-proportioned, and obvious characteristics ofthe restoration appears at1200℃.（2）Surface of neutron irradiated SiC annealed up to1200℃appears a lot ofcavities.It may be due to a kind of complex defect（holes） to form in the process ofradiation and grow up with the increasing temperature.（3）Full width at half maximum（FWHM） of neutron irradiated SiC shows agood linear law a700℃.FWHM decreased linearly from700℃. High-temperaturedetector under extreme condition can be made according to it.（4）PL spectra of neutron-irradiated SiC after annealing at1400℃showed astrong300nm green emission peak, which is overlying of504、545and570nm. Theresult may provide a reference for the manufacture of green light electrical devices.（5）Neutron-irradiation can induce the formation of [Al-O]^3-color center inaddition to F₂, F₂⁺, F₂²⁺, and F₃color centers inAl₂O₃.657nm emission peak of therare reports at home and abroad was detected in PL spectra.And only the657nmpeak can survive after800°C annealing process and might originate from antisite Aldefects （AlO）.