Structure and Hydrogen Permeation of Ni-Nb-Zr Amorphous Alloys

摘要

The local structures around Zr atoms in as-quenched and hydrogenated (Ni_(60Nb_(40))_(100-x) Zr_x (x=30 and 50) amorphous alloys were studied by means of extended x-ray absorption fine structure (EXAFS) and x-ray diffraction. The permeability of the (Ni_(60)Nb_(40))_(100-x)Zr_x amorphous alloys increases with increasing Zr content. The local structure analyses around Zr atoms by EXAFS for the (Ni_(60)Nb_(40))_(100-x)Zr_x amorphous alloys show that the inter-atomic distance of Zr-Zr correlation expands from 3.16 to 3.34A by hydrogenation while there is no change for that Zr-Ni pairs. The similar features are observed in x-ray diffraction analysis. These results indicate that the Zr-Zr bond length is expanded by hydrogen atoms, and hydrogen atoms can easily permeate through these Zr-rich region.