Structure and Thermal Stability of Amorphous Ni₈₄Y₈Kr₈ Alloy

Abstract

The structural studies of amorphous Ni84Y8Kr8 alloy have been performed by means of X-ray diffraction combined with DTA/TG, TEM and SEM experiments. The local structure of this amorphous alloy appears to be well represented by a mixture of noncrystalline microstructures with short-range interatomic distances similar to crystalline Ni9.4Y, Ni and Kr. The X-ray diffraction pattern at 300°C demonstrated the occurrence of crystallization. Initially, the diffraction peaks can be indexed as a mixture of Ni9.4Y and Ni phases, and Ni9.4Y decomposes into Ni and Ni5Y at higher temperatures. X-ray diffraction measurements exhibit the formation of solid fcc Kr bubbles or precipitates above 540°C. The rapid release of Kr does not occur below 700°C.