Origin of high elastic strain in amorphous silica nanowires

An understanding of the origin of elastic strain is extremely important for both crystalline materials and amorphous materials. Owing to the lack of a long range order in their structure, it is arduous to dynamically study the elastic mechanism of amorphous materials experimentally at atomic scale compared with their crystalline counterparts. Here, the elastic deformation mechanism of amorphous silica nanowires (NWs) has been studied for the first time via in situ elastic tensile tests in a transmission electron microscope. Radial distribution functions (RDFs) calculated from the corresponding selected area electron diffraction patterns (SAEDPs) at different strains were used to reconstruct a structural model based on the reverse Monte-Carlo (RMC) method. The result interestingly indicates that the elastic strain of silica glass NWs can be mainly attributed to the elastic elongation of the bond length accompanied by a change in the bond angle distribution. This work is useful for understanding the high strength of amorphous materials.