ss-relaxation related bright bands in thin film metallic glasses: Localized percolation of flow units captured via transmission electron microscope

摘要

We report that ss-relaxation of amorphous NiW alloy film was effectively enhanced by adding two thin crystalline layers into the amorphous layer. Correspondingly, more bright bands, i.e., nano shear bands, were captured in the amorphous layer, which experienced more pronounced ss-relaxations. Based on the potential energy landscape theory, the bright band was proposed to be the localized percolation of flow units corresponding to ss-relaxation. Our findings may help connecting experimentally ss-relaxation with flow units and shed light on the microstructure origin of ss-relaxation.