Vein pattern vs. columnar fracture shape in Cu-Zr thin film metallic glasses: Driving force and mechanism

Numerous studies have been published in the past showing the presence of vein-like or columnar fracture shapes in thin film metallic glasses (TFMGs), while the reason behind the different features remains poorly understood. This study uncovers the reason behind this phenomenon in Cu-Zr TFMGs’ by considering experimental evidence and analysis. Oxidation during deposition is the reason for the presence of the columnar feature after the cleavage, as shear banding cannot raise the temperature enough for the regional melting process to end up in the vein pattern. In several studies, unnoticed or unreported oxygen is proposed to be the reason for reporting metallic glasses' columnar cross-sections.