Ultrahigh Tensile Ductility of Ag2Te Nanowire at Room Temperature

Abstract Tensile ductility is one of the key concerns in the field of flexible devices. Ag 2 Te is a promising flexible thermoelectric (TE) material due to its high TE properties and compressive ductility, but low tensile ductility blocks its flexible application. In this work, a low‐dimensional strategy is adopted to find that Ag 2 Te nanowires exhibit an exceptional tensile fracture strain of 75.7% at room temperature, several times higher than other ceramic and semiconductor nanowires, and even comparable to some metals. By in situ transmission electron microscope (TEM) observations and density functional theory (DFT) calculations, the tensile ductile mechanism has been successfully revealed. First, the emissions of partial dislocations from the surface lead to the slipping band along (100) plane, which is attributed to the atomic rearrangement along (100) plane. Then, the surface steps occur, and deformation twinning forms along (001) plane at the slip region, which inhibits the crack initiation. Finally, Ag particles precipitate around the slip region and then form Ag nanobridges to further resist the external deformation, achieving extraordinary tensile ductility. This work provides some insights into the mechanical behaviors of Ag 2 Te at the nanoscales, which is beneficial for the development of reliable micro‐devices.