Most engineering materials are based on multiphase microstructures produced either through the control of phase equilibria or by the fabrication of different materials as in thin-film processing. In both processes, the microstructure relaxes towards equilibrium by mismatch dislocations (or geometric misfit dislocations) across the heterophase interfaces^1,2,3,4,5. Despite their ubiquitous presence, directly probing the dynamic action of mismatch dislocations has been unachievable owing to their buried nature. Here, using the interfacial transformation of copper oxide to copper as an example, we demonstrate the role of mismatch dislocations in modulating oxide-to-metal interfacial transformations in an intermittent manner, by which the lateral flow of interfacial ledges is pinned at the core of mismatch dislocations until the dislocation climbs to the new oxide/metal interface location. Together with atomistic calculations, we identify that the pinning effect is associated with the non-local transport of metal atoms to fill vacancies at the dislocation core. These results provide mechanistic insight into solid–solid interfacial transformations and have substantial implications for utilizing structural defects at buried interfaces to modulate mass transport and transformation kinetics.

大多数工程材料基于多相微结构，通过控制相平衡或通过制造不同材料（如在薄膜加工中）产生。在这两个过程中，微观结构通过跨异相界面的失配位错（或几何失配位错）向平衡松弛^1,2,3,4,5. 尽管它们无处不在，但由于它们的埋藏性质，直接探测错配位错的动态作用是无法实现的。在这里，以氧化铜到铜的界面转变为例，我们展示了错配位错在以间歇方式调节氧化物到金属的界面转变中的作用，通过这种方式，界面凸台的横向流动被固定在错配位错直到位错爬升到新的氧化物/金属界面位置。结合原子计算，我们确定钉扎效应与金属原子的非局​​部传输以填充位错核心的空位有关。