Dimension-dependent mechanical features of Au-nanocrystalline nanofilms

Ma, Lijun, Du, Lena, Wang, Shu, Wang, Qing, Xue, Shifeng, Zhu, Hanxing ORCID: https://orcid.org/0000-0002-3209-6831 and Liu, Qian 2023. Dimension-dependent mechanical features of Au-nanocrystalline nanofilms. Nano Research 16 (12) , pp. 13400-13408. 10.1007/s12274-023-6091-2 Item availability restricted.

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Abstract

For metal nanofilms composed of nanocrystals, the multiple deformation mechanisms will coexist and bring unique and complex elastic-plastic and fracture mechanical properties. By successfully fabricating large quantities of uniform doubly-clamped suspended gold (Au) nanobeams with different thicknesses and nanograin sizes, we obtain full-spectrum mechanical features with statistical significance by combining atomic force microscopy (AFM) nanoindentation experiments, nonlinear theoretical model, and numerical simulations. The yield and breaking strengths of the Au nanobeams have a huge increase by nearly an order of magnitude compared with bulk Au and exhibit strong nonlinear effects, and the corresponding strong-yield ratio is up to 4, demonstrating extremely high strength reserve and vibration resistance. The strong-yield ratio gradually decreases with decreasing thickness, identifying a conversion of the failure type from ductile to brittle. Interestingly, the Hall–Petch relationship has been identified to be still valid at the nanoscale, and K in the equation reaches 4.8 Gpa·nm1/2, nearly twice of bulk nanocrystalline Au, which is ascribed to the coupling effect of nanocrystals and nanoscale thickness.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Engineering
Publisher:	Springer
ISSN:	1998-0124
Date of First Compliant Deposit:	16 August 2023
Date of Acceptance:	13 August 2023
Last Modified:	15 Jan 2024 18:31
URI:	https://orca.cardiff.ac.uk/id/eprint/161832

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