α-Al_2O_3单晶的中子辐照效应研究

Investigation of Radiation Effects of α-Al_2O_3 Single Crystal by Neutrons

选用能量为0.1～500MeV、总注量为1.0×1018neutron/cm2的快中子对α-Al2O3单晶进行辐照。采用吸收光谱和荧光光谱研究了α-Al2O3单晶经辐照后的缺陷形成及光学性能变化。α-Al2O3单晶经快中子辐照后出现着色现象,在206、228及256nm等处出现吸收峰。荧光光谱出现了326、331及379nm等荧光吸收峰值。分析表明,中子辐照在α-Al2O3单晶中产生了F+、F2及F3+等色心类型,该类吸收色心起源于α-Al2O3单晶中氧空位,并计算了辐照退火前后的色心浓度N。正电子湮没寿命结果表明,经快中子辐照后,α-Al2O3单晶产生单空位及多空位,且多空位浓度增大幅度比单空位的增大幅度大。

The fast neutron with the energy of 0.1-500 MeV and the dose with 1.0-1018 neutron/cm^2 was chosen to irradiate α-Al2O3 single crystal. The formation of defects and the change of optical property were studied by absorption and luminescence spectra. The results showed that α-Al2O3 single crystal was colored up by the irradiation of neutron and there were absorption peaks at 206, 228 and 256 nm, etc. There were also luminescence peaks at 326; 331 and 379 nm, etc. It was founded that there were many color centers, such as F^＋, F2, F^3＋ color centers, in α-Al2O3 single crystal after neutron irradiation. The study indicated that the color center was due to the origin of oxygen vacancy. The concentration N of color centers were calculated. The result of PAT indicated that there were vacancies in α-Al2O3 single crystal after neutron irradiation and the increase of single-vacancy was greater than that of multiple-vacancy.