Li Mingqiang, Shen Yidi, Luo Kun, An Qi, Gao Peng, Xiao Penghao, Zou Yu
Department of Materials Science and Engineering, University of Toronto, Toronto, Ontario, Canada.
Electron Microscopy Laboratory and International Center for Quantum Materials, School of Physics, Peking University, Beijing, China.
Nat Mater. 2023 Aug;22(8):958-963. doi: 10.1038/s41563-023-01572-7. Epub 2023 Jun 19.
Dislocation motion, an important mechanism underlying crystal plasticity, is critical for the hardening, processing and application of a wide range of structural and functional materials. For decades, the movement of dislocations has been widely observed in crystalline solids under mechanical loading. However, the goal of manipulating dislocation motion via a non-mechanical field alone remains elusive. Here we present real-time observations of dislocation motion controlled solely by using an external electric field in single-crystalline zinc sulfide-the dislocations can move back and forth depending on the direction of the electric field. We reveal the non-stoichiometric nature of dislocation cores and determine their charge characteristics. Both negatively and positively charged dislocations are directly resolved, and their glide barriers decrease under an electric field, explaining the experimental observations. This study provides direct evidence of dislocation dynamics controlled by a non-mechanical stimulus and opens up the possibility of modulating dislocation-related properties.
位错运动是晶体塑性的一个重要机制，对于广泛的结构和功能材料的硬化、加工及应用至关重要。几十年来，在机械载荷作用下，位错运动已在晶体固体中被广泛观测到。然而，仅通过非机械场来操控位错运动这一目标仍难以实现。在此，我们展示了在单晶硫化锌中仅利用外部电场对 位错运动进行的实时观测——位错可根据电场方向来回移动。我们揭示了位错核心的非化学计量性质，并确定了它们的电荷特性。带负电和带正电的位错都被直接分辨出来，并且它们在电场下的滑移势垒降低，这解释了实验观测结果。这项研究提供了由非机械刺激控制位错动力学的直接证据，并开启了调节与位错相关特性的可能性。
