Deformation-mediated phase transformation in gold nano-junction

To further advance our understanding of the mechanical behavior of nano-sized crystals, it is important to visualize the deformation process in the real material system. In this work, body-centered-tetragonal (BCT) lattice was observed during in-situ tension of gold nano-junction in a transmission electron microscope, which is well explained by the proposed deformation mechanism. In contrast to the well-known Bain model, the phase transformation can be realized by a progressively slipping process with a vector of 1/12<112>. The lattice constant a can be accurately predicated from a hard-sphere model and c is about 5% larger than that in MD simulations using a more realistic interatomic potential.

► In-situ tension of Au nano-junction was conducted in TEM. ► Phase transformation from FCC to BCT in gold nano-junction was observed. ► A deformation mechanism was proposed to explain the phase transition. ► A slip process with a vector of 1/12<112> results in a BCT structure.