Ir是一种重要的真空紫外反射材料,在太阳物理、宇宙物理、生命科学、大气物理、同步辐射等方面有着十分重要的应用。对电子束蒸发沉积Ir膜在真空紫外波段的反射特性进行了系统的理论和实验研究。根据吸收材料基底上单层金属膜数学计算模型,对不同基片上各种厚度的Ir膜真空紫外反射率进行了优化计算。根据计算和前期实验结果,采用电子束蒸发方法,在石英、K9玻璃基片上沉积了不同厚度的Ir膜,在入射波长120 nm处获得了近30％正入射反射率,对应的Ir膜厚度为12 nm。过厚或过薄均不利于Ir膜反射率的提高。经退火处理后,Ir膜中张应力有所释放但并未消除,同时晶粒平均尺寸显著增大,反射率下降。

Ir is an important vacuum-ultraviolet (VUV) reflecting material, and has various applications in hi-tech fields including solar physics, cosmic physics, life science, and synchrotron radiation. The reflective performance of Ir film in the VUV wavelength region was studied theoretically and experimentally. Based on the theoretical model of single metal layer on absorbing substrate, the optimum calculation was performed for Ir layer of various thickness on K9 glass and quartz substrate in the VUV wavelength region. Considering the calculation results and previous research, single layer Ir films of different thickness were fabricated on K9 glass and quartz substrate by electron gun evaporation system, and nearly 30％ normal incident reflectivity at 120 nm incident wavelength was obtained, which corresponded to the optimum thickness of Ir layer of 12 nm. Ir layer of too thin or thick thickness cannot get high reflectivity. The annealing of the layer benefits the release of tension, but it also causes the increase of average size of Ir grain and degradation of the reflectivity.