High uniaxial buckling strain for measuring the mechanical properties of nanoporous gold films

Abstract

Excellent studies have been conducted to understand the mechanical behavior of thin films by buckling the films using heat-shrinkable substrates. A buckling-based method [Stafford et al., Nat. Mater. 3 (2004) 545] has been adopted to measure the mechanical properties of nanoporous gold (NPG) films. This method is highly suitable under low-strain conditions; however, we attempted to use this approach under high-strain conditions. The calculated (8.2 GPa) and measured (10 +/- 1.3 GPa) values of Young's modulus are remarkably near the literature value (8.8 GPa). Owing to the high-strain conditions, the effects of pore size on the Young's modulus [J. Erlebacher, J. Mathur, Appl. Phys. Lett. 90 (2007) 061910] may not be considered, and the cracks and delamination of the NPG films from the shrunken substrate were considered to interpret the mechanical behavior of the films. (c) 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.