A deeper understanding of vacancy-induced effects in ceramics may lead to optimized material design and improved mechanical properties. However, current research primarily focuses on the impact of vacancies on the intrinsic mechanical properties of materials, lacking direct experimental validation of their mechanical response behavior. In this study, we closely investigate the influence of Schottky-vacancy defects introduced during the deposition process on the mechanical behavior of MoN/TiN superlattice. In the as-deposited coating, Schottky vacancies are found to be distributed inside MoN as clusters. By coupling FIB with cross-sectional TEM observation, we further reveal Schottky vacancies evolution under loads at the atomic level and their significant impact on superlattice deformation. These Schottky vacancies promote superlattice intermixing and weaken the interface-strengthening effect. However, they are also beneficial to dislocation nucleation and increase the nitride plastic deformability. These findings provide a new perspective on the impact of point defects on the mechanical properties of ceramic materials.

中文翻译：

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直接观察肖特基空位簇及其在 MoN/TiN 超晶格中的机械响应


更深入地了解陶瓷中空位诱导效应可能会导致优化材料设计和改善机械性能。然而，目前的研究主要集中在空位对材料固有机械性能的影响，缺乏对其机械响应行为的直接实验验证。在这项研究中，我们仔细研究了沉积过程中引入的肖特基空位缺陷对 MoN/TiN 超晶格机械行为的影响。在沉积的涂层中，发现肖特基空位以团簇的形式分布在 MoN 内部。通过将 FIB 与横截面 TEM 观察耦合，我们进一步揭示了原子水平载荷下的肖特基空位演变及其对超晶格变形的显着影响。这些肖特基空位促进了超晶格混化并削弱了界面强化效应。然而，它们也有利于位错成核并增加氮化物塑性变形能力。这些发现为点缺陷对陶瓷材料力学性能的影响提供了新的视角。