Stress-Induced Structural Transformations in Au Nanocrystals

Abhinav Parakh, Sangryun Lee, Mehrdad T. Kiani, David Doan, Martin Kunz, Andrew Doran, Seunghwa Ryu, X. Wendy Gu

Research output: Contribution to journalArticlepeer-review

9 Scopus citations


Nanocrystals can exist in multiply twinned structures like icosahedron or single crystalline structures like cuboctahedron. Transformations between these structures can proceed through diffusion or displacive motion. Experimental studies on nanocrystal structural transformations have focused on high-temperature diffusion-mediated processes. Limited experimental evidence of displacive motion exists. We report structural transformation of 6 nm Au nanocrystals under nonhydrostatic pressure of 7.7 GPa in a diamond anvil cell that is driven by displacive motion. X-ray diffraction and transmission electron microscopy were used to detect the structural transformation from multiply twinned to single crystalline. Single crystalline nanocrystals were recovered after unloading, then quickly reverted to the multiply twinned state after dispersion in toluene. The dynamics of recovery was captured using TEM which showed surface recrystallization and rapid twin boundary motion. Molecular dynamics simulations showed that twin boundaries are unstable due to defects nucleated from the interior of the nanocrystal.

Original languageEnglish
Pages (from-to)7767-7773
Number of pages7
JournalNano Letters
Issue number10
StatePublished - 14 Oct 2020

Bibliographical note

Publisher Copyright:
Copyright © 2020 American Chemical Society.


  • Asymmetric Mackay-like Transformation
  • Diamond Anvil Cell
  • Transmission Electron Microscopy, Molecular Dynamics Simulation
  • X-ray Diffraction


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