Zhang Jiawen, Preuß Oliver, Fang Xufei, Lu Wenjun
Shenzhen Key Laboratory of Intelligent Robotics and Flexible Manufacturing Systems, Department of Mechanical and Energy Engineering, Southern University of Science and Technology, Shenzhen, 518055 China.
Department of Materials and Earth Sciences, Technical University of Darmstadt, Peter-Grünberg-Str. 2, 64287 Darmstadt, Germany.
JOM (1989). 2025;77(5):3503-3512. doi: 10.1007/s11837-025-07148-x. Epub 2025 Jan 27.
Dislocations in functional oxides have sparked interest in the potential they hold for harvesting both enhanced mechanical and functional properties for next-generation electronic devices. This has motivated the recent research endeavor to achieve tunable dislocation density and plastic zone size in functional oxides. However, the dislocation density-dependent micro-/nanomechanical properties in functional ceramics have yet to be assessed, which will be critical for the design of reliable electronic devices in the near future. In this work, we use a model material, single-crystal SrTiO, as one of the most widely used substrates for oxide electronics, to assess the hardness and fracture behavior at micro-/nanoscale by pre-engineering the dislocation densities from ~ 10 m up to ~ 4.0 × 10 m. We find crack suppression and enhanced hardness during nanoindentation in samples with pre-engineered dislocations. Post-indentation analysis using transmission electron microscopy revealed the critical role of pre-existing dislocations in regulating the crack suppression and increased hardness in SrTiO. The results can help guide the design of mechanically reliable electronics via dislocation engineering.
功能氧化物中的位错引发了人们对其为下一代电子设备获取增强的机械性能和功能特性的潜力的兴趣。这推动了近期在功能氧化物中实现可调节位错密度和塑性区尺寸的研究努力。然而，功能陶瓷中位错密度依赖的微/纳米力学性能尚未得到评估，这对于在不久的将来设计可靠的电子设备至关重要。在这项工作中，我们使用一种模型材料——单晶SrTiO（作为氧化物电子学中使用最广泛的衬底之一），通过将位错密度从约10¹⁴ m⁻²预先设计到约4.0×10¹⁶ m⁻²来评估微/纳米尺度下的硬度和断裂行为。我们发现在具有预先设计位错的样品的纳米压痕过程中出现了裂纹抑制和硬度增强现象。使用透射电子显微镜进行的压痕后分析揭示了预先存在的位错在调节SrTiO中的裂纹抑制和硬度增加方面的关键作用。这些结果有助于通过位错工程指导机械可靠电子设备的设计。
