Nitridated Ru/B4C multilayer mirrors with improved interface structure, zero stress, and enhanced hard X-ray reflectance

• DOI: 10.1364/oe.26.021803
• Publication Date: 2018-08-08T12:38:41Z
• Authors: Qiushi Huang; Yang Liu; Yang Yang; Runze Qi; Yufei Feng; Igor V. Kozhevnikov; Wenbin Li; Zhong Zhang; Hui Jiang; Ling Zhang; Aiguo Li; Jie Wang; Zhanshan Wang
• Keywords: X-ray reflectivity

Ru/B4C multilayer mirrors are used for hard X-ray monochromators with moderate spectral resolution and high integral flux. To overcome the problem of large compressive stress inherent in multilayers, a reactive sputtering technique using mixture working gas argon nitrogen different partial pressures was tested, fabricated multilayers had period 3 nm. The intrinsic essentially reduced after nitridation relaxed to zero value at approximately 15% pressure gas. Interface roughness slightly increased which can be caused by polycrystalline structure inside nitridated samples. More importantly, showed an enhanced reflectance (67% 8.04 keV photon energy) as compared one pure Ar (54%). analysis transmission electron microscopy photoelectron spectroscopy demonstrated that incorporated into mostly located B4C layers forming BN compounds, suppressed diffusion boron, stabilized interfaces reflectance.