Morphology of Buried Interfaces in Ion-Assisted Magnetron Sputter-Deposited 11B4C-Containing Ni/Ti Multilayer Neutron Optics Investigated by Grazing-Incidence Small-Angle Scattering

• DOI: 10.1021/acsami.4c01457
• Publication Date: 2024-04-22T11:26:25Z
• Authors: Sjoerd Stendahl; Naureen Ghafoor; Matthias Schwartz...; Anton Zubayer; Jens Birch; Fredrik Eriksson
• Keywords: Grazing-incidence small-angle scattering; Small-Angle Scattering

Multilayer neutron optics require precise control of interface morphology for optimal performance. In this work, we investigate the effects different growth conditions on Ni/Ti-based multilayers, with a focus incorporating low-neutron-absorbing 11B4C and using ion assistance schemes. Grazing-incidence small-angle X-ray scattering was used to probe structural morphological details buried interfaces, revealing that layers become more strongly correlated interfaces form mounds increasing amounts 11B4C. Applying high flux during can reduce mound formation but lead mixing, while modulated scheme an initial buffer layer grown at low energy top higher prevents intermixing. The condition found be adding 26.0 atom % combined assistance. A multilayer period 48.2 Å 100 periods under these conditions, coupled fitting reflectivity data revealed average width only 2.7 Å, significant improvement over current state-of-the-art commercial Ni/Ti multilayers. Overall, our study demonstrates addition use significantly improve leading improved