Ion irradiation induced phase transformation in gold nanocrystalline films

Pranav K Suri; James E Nathaniel 2nd; Nan Li; Jon K Baldwin; Yongqiang Wang; Khalid Hattar; Mitra L Taheri

doi:10.1038/s41598-020-74779-2

Ion irradiation induced phase transformation in gold nanocrystalline films

Sci Rep. 2020 Oct 20;10(1):17864. doi: 10.1038/s41598-020-74779-2.

Authors

Pranav K Suri^{1

2}, James E Nathaniel 2nd^{1

3}, Nan Li⁴, Jon K Baldwin⁴, Yongqiang Wang⁵, Khalid Hattar⁶, Mitra L Taheri^{7

8}

Affiliations

¹ Department of Materials Science and Engineering, Drexel University, Philadelphia, PA, USA.
² Micron Technology, Inc., Boise, ID, USA.
³ Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD, USA.
⁴ MPA Division, Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, USA.
⁵ MST-8, Los Alamos National Laboratory, Los Alamos, NM, USA.
⁶ Sandia National Laboratories, Albuquerque, NM, USA.
⁷ Department of Materials Science and Engineering, Drexel University, Philadelphia, PA, USA. mtaheri4@jhu.edu.
⁸ Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD, USA. mtaheri4@jhu.edu.

Abstract

Gold is a noble metal typically stable as a solid in a face-centered cubic (FCC) structure under ambient conditions; however, under particular circumstances aberrant allotropes have been synthesized. In this work, we document the phase transformation of 25 nm thick nanocrystalline (NC) free-standing gold thin-film via in situ ion irradiation studied using atomic-resolution transmission electron microscopy (TEM). Utilizing precession electron diffraction (PED) techniques, crystallographic orientation and the radiation-induced relative strains were measured and furthermore used to determine that a combination of surface and radiation-induced strains lead to an FCC to hexagonal close packed (HCP) crystallographic phase transformation upon a 10 dpa radiation dose of Au⁴⁺ ions. Contrary to previous studies, HCP phase in nanostructures of gold was stabilized and did not transform back to FCC due to a combination of size effects and defects imparted by damage cascades.

Abstract

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