X-ray broadband Ni/SiC multilayers: improvement with W barrier layers

作者:Emprin B*; Troussel Ph; Soullie G; Stemmler Ph; Mercere P; Meltchakov E; Jerome A; Delmotte F
来源:Optics Express, 2014, 22(21): 25853-25865.
DOI:10.1364/OE.22.025853

摘要

We present an experimental study and performance improvement of periodic and aperiodic Ni/SiC multilayer coatings. Periodic Ni/SiC multilayer mirrors have been coated and characterized by grazing incidence X-ray reflectometry at 8.048 keV (Cu K alpha radiation) and by measurements at 3 keV and 5 keV on synchrotron radiation facilities. An interdiffusion effect is found between Ni and SiC layers. A two-material model, NixSiy/SiC, using a silicide instead of Ni, was used to fit the measurements. The addition of 0.6 nm W barrier layers at the interfaces allows a significant reduction of the interdiffusion between Ni and SiC. In order to obtain a specific reflectivity profile in the 2 - 8 keV energy range, we have designed and coated aperiodic multilayer mirrors by using Ni/SiC with and without W barrier layers. The experimental reflectivity profiles as a function of the photon energy were measured on a synchrotron radiation facility in both cases. Adding W barrier layers in Ni/SiC multilayers provides a better precision on the layer thicknesses and a very good agreement between the experimental data and the targeted spectral profile.

  • 出版日期2014-10-20
  • 单位中国地震局