Ultra‐Large Compressive Plasticity of E‐Ga₂O₃ Thin Films at the Submicron Scale

Abstract Gallium oxide (Ga₂O₃) usually fractures in the brittle form, and achieving large plastic deformability to avoid catastrophic failure is in high demand. Here, ε‐Ga₂O₃ thin films with columnar crystals and partial unoccupied Ga sites are synthesized, and it is demonstrated that the ε‐Ga₂O₃ at the submicron scale can be compressed to an ultra‐large plastic strain of 48.5% without cracking. The compressive behavior and related mechanisms are investigated by in situ transmission electron microscope nanomechanical testing combined with atomic‐resolution characterizations. The serrated plastic flow and large strain burst are two major deformation forms of ε‐Ga₂O₃ during compression, which are attributed to the dislocation nucleation and avalanches, formation of new grains, and amorphization. The ultra‐large compressive plasticity of ε‐Ga₂O₃ thin films at the submicron scale can inspire new applications of Ga₂O₃ in micro‐ or nano‐ electronic and optoelectronic devices, especially those that require impact resistance during processing or service.