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Indexed by:期刊论文

Date of Publication:2012-08-01

Journal:JOURNAL OF NON-CRYSTALLINE SOLIDS

Included Journals:SCIE、EI

Volume:358

Issue:15

Page Number:1730-1734

ISSN No.:0022-3093

Key Words:Ab initio molecular dynamics; Ni-Ta metallic glass; Chemical short-range order; Elastic properties; Electronic structures

Abstract:Ni-Ta bulk metallic glass (BMG) with compositions around Ni60Ta40 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 Ni60Ta40 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 Ni7Ta6 clusters as the major Ni-centered clusters, while the most popular Ta-centered cluster is Ta7Ni8. These findings agree with our previous cluster model of Ni-Ta binary BMG. The elastic moduli of Ni60Ta40 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. (C) 2012 Elsevier B.V. All rights reserved.