First-principles study of the binary Ni60Ta40 metallic glass: The atomic structure and elastic properties

Abstract Ni–Ta bulk metallic glass (BMG) with compositions around Ni 60 Ta 40 is a newly found binary BMG with high glass forming ability and extraordinary mechanical strength. Using ab initio molecular dynamics, the local atomic structure, elastic properties and electronic structures of Ni 60 Ta 40 glass have been explored. The pair-correlation functions, coordination numbers, and chemical compositions of the most abundant local clusters have been analyzed. We demonstrated the existence of icosahedral Ni 7 Ta 6 clusters as the major Ni-centered clusters, while the most popular Ta-centered cluster is Ta 7 Ni 8 . These findings agree with our previous cluster model of Ni–Ta binary BMG. The elastic moduli of Ni 60 Ta 40 glass were also computed and the experimental Young's modulus is well reproduced. Analysis of electronic structures further revealed that the interaction between d electrons of Ni and Ta atoms is responsible for the experimentally observed ultrahigh mechanical strength for the Ni–Ta BMGs.