High pressure atomic structure of Zr–Cu metallic glass via EXAFS spectroscopy and molecular dynamics simulations. Issue 1 (2nd January 2020)

• Record Type: Journal Article
• Authors: Dziegielewski, P.; Mathon, O.; Kantor, I.; Pascarelli, S.; Shinmei, T.; Irifune, T.; Antonowicz, J.
• Is Part Of: High pressure research. Volume 40:Issue 1(2020)
• Page Start: 54
• Page End: 64
• Publication Date: 2020-01-02
• Subjects: Metallic glasses -- high pressure -- EXAFS -- atomic structure -- icosahedral order; High pressure (Science) -- Periodicals; High pressure (Technology) -- Periodicals; 536.41
• DOI: 10.1080/08957959.2019.1695797
• Languages: English
• ISSNs: 0895-7959

Abstract

ABSTRACT: In this work, we use extended X-ray absorption fine structure (EXAFS) data collected using nano-polycrystalline diamond anvil cell to study the atomic arrangement in Zr–Cu metallic glass in high pressure (HP) conditions. To reveal the microscopic details of stress accommodation mechanism, we performed molecular dynamics (MD) simulations of the HP atomic arrangement. By comparing the experimental and the calculated Zr and Cu K-edge EXAFS signal we prove the realistic character of the computer simulations. A detailed geometrical analysis of the simulated atomic configurations shows that with increasing hydrostatic pressure the local structure of Zr–Cu amorphous alloy becomes gradually dominated by Cu-centred icosahedral structural motifs involving fivefold symmetry incompatible with crystalline ordering. The variation of the short-range order is attributed to preferential straining of mechanically soft bonds between zirconium atoms.