Nanocolumnar ZrCu thin film metallic glass with tailored mechanical and electrical properties

Thin-film metallic glasses (TFMGs) are promising materials for flexible electronics due to their large deformability and metallic-like electrical conductivity. Here, we synthesize homogeneous and nanocolumnar ZrCu TFMGs with tailored column size ranging from 16 up to 60 nm, investigating the relationship among atomic structure, electrical and mechanical properties focusing on their potential applications in flexible electronics. Tracer diffusion experiments indicate an absence of macroscopic cracks and enhanced diffusion coefficient for nanocolumnar TFMGs, up to one order of magnitude higher than in homogeneous counterpart, due to the presence of intercolumnar interfaces. We show that electrical resistivity increases with decreasing column size (from 570.0 ± 11.6 down to 285.9 ± 12.6 µΩ × cm) due to the enhanced electron scattering events at intercolumnar interfaces. Tensile tests on polymeric substrates reveal that the crack onset strain increases from 0.8 ± 0.05 up to 1.6 ± 0.05 % for large diameter nanocolumns due to the lower density of intercolumnar interfaces and presence of strong Cu-Cu bonds. Overall, we show how nanoengineering design concepts can be applied to TFMGs to tune their mechanical and electrical performance by controlling the nanocolumnar growth, paving the way for their potential applications in flexible electronics.