Dong Zhaohui, Zhang Xiuyu, Li Jiling, Peng Shengyuan, Wan Qiang, Xue Jianming, Yi Xin
School of Traffic Management, People's Public Security University of China, Beijing 100038, China.
Institute of Electronic Engineering, China Academy of Engineering Physics, Mianyang 621999, China.
Materials (Basel). 2023 Dec 6;16(24):7537. doi: 10.3390/ma16247537.
Understanding the impact of irradiation and temperature on the mechanical properties of GaN single crystals holds significant relevance for rational designs and applications of GaN-based transistors, lasers, and sensors. This study systematically investigates the influence of C-ion irradiation and temperature on pop-in events, hardness, Young's modulus, and fracture behavior of GaN single crystals through nanoindentation experiments. In comparison with unirradiated GaN samples, the pop-in phenomenon for ion-irradiated GaN samples is associated with a larger critical indentation load, which decreases with increasing temperature. Both unirradiated and ion-irradiated GaN samples exhibit a decline in hardness with increasing indentation depth, while Young's moduli do not exhibit a clear size effect. In addition, intrinsic hardness displays an inverse relationship with temperature, and ion-irradiated GaN single crystals exhibit greater intrinsic hardness than their unirradiated counterparts. Our analysis further underscores the significance of Peierls stress during indentation, with this stress decreasing as temperature rises. Examinations of optical micrographs of indentation-induced fractures demonstrate an irradiation embrittlement effect. This work provides valuable insights into the mechanical behavior of GaN single crystals under varying irradiation and temperature conditions.
了解辐照和温度对氮化镓（GaN）单晶力学性能的影响对于基于GaN的晶体管、激光器和传感器的合理设计与应用具有重要意义。本研究通过纳米压痕实验系统地研究了碳离子辐照和温度对GaN单晶的压入事件、硬度、杨氏模量和断裂行为的影响。与未辐照的GaN样品相比，离子辐照的GaN样品的压入现象与更大的临界压痕载荷相关，该载荷随温度升高而降低。未辐照和离子辐照的GaN样品的硬度均随压痕深度增加而下降，而杨氏模量未表现出明显的尺寸效应。此外，本征硬度与温度呈反比关系，离子辐照的GaN单晶比未辐照的具有更高的本征硬度。我们的分析进一步强调了压痕过程中派尔斯应力的重要性，该应力随温度升高而降低。对压痕诱导断裂的光学显微镜检查表明存在辐照脆化效应。这项工作为不同辐照和温度条件下GaN单晶的力学行为提供了有价值的见解。
