Sung Zuhawn, Cano Arely, Murthy Akshay, Bafia Daniel, Karapetrova Evguenia, Martinello Martina, Lee Jaeyel, Grassellino Anna, Romanenko Alexander
Fermi National Accelerator Laboratory, Batavia, IL, 60510, USA.
Center for Research and Advanced Studies of the National Polytechnic Institute, Mexico City, Mexico.
Sci Rep. 2024 Nov 6;14(1):26916. doi: 10.1038/s41598-024-77905-6.
Superconducting niobium serves as a key enabling material for superconducting radio frequency (SRF) technology as well as quantum computing devices. Niobium has a high propensity for the uptake of hydrogen. At room temperature, hydrogen commonly occupies tetragonal sites in the Nb lattice as the metal (M)-gas (H) phase. When the temperature is decreased, however, a solid solution of Nb-H begins to precipitate. In this study, we show the first identified topographical features associated with nanometer-size hydride phase (NbH) precipitates on the surface of the metallic superconducting niobium using cryogenic-atomic force microscopy (AFM). Further, high energy grazing incidence X-ray diffraction reveals information regarding the structure and stoichiometry of these precipitates. Finally, through time-of-flight secondary ion mass spectroscopy (ToF-SIMS), we locate atomic hydrogen sources near the top surface. This systematic study clarifies nanometer scale hydrides precipitated on the surface of the SRF Nb cavity that exhibit performance degradation at a high accelerating field regime.
超导铌是超导射频（SRF）技术以及量子计算设备的关键支撑材料。铌具有很强的吸氢倾向。在室温下，氢通常以金属（M）-气体（H）相占据铌晶格中的四方位置。然而，当温度降低时，Nb-H固溶体开始析出。在本研究中，我们首次使用低温原子力显微镜（AFM）展示了与金属超导铌表面纳米尺寸氢化物相（NbH）析出物相关的地形特征。此外，高能掠入射X射线衍射揭示了这些析出物的结构和化学计量信息。最后，通过飞行时间二次离子质谱（ToF-SIMS），我们在顶面附近定位了原子氢源。这项系统研究阐明了在高加速场条件下表现出性能退化的SRF铌腔表面析出的纳米级氢化物。
