EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

The limited ductility of metallic thin films (< 1%) poses a challenge to flexible electronics applications. There are only few exceptions to this rule. For this study, we selected remarkable gold films with a ductility > 10% and engaged into advanced nanomechanical characterization to identify the underlying physical mechanisms. From in-situ microtensile tests in a transmission electron microscope, it was found that their microstructure favors grain boundary sliding (GBS) and shear coupled grain boundary migration (SCGBM). The exceptional ductility of the samples was rationalized as a consequence of these mechanisms preventing strain localization. Since the new mechanisms were evidenced at room temperature and under strain-rate conditions typical for most applications, the findings open up new perspectives for developing ductile metallic films by microstructural engineering.