Fracture experiments to evaluate the cleavage energy of the (110)[1-10] and (111)[11-2] cleavage systems in silicon at room temperature and humidity give 2.7 +/- 0.3 and 2.2 +/-0.2 J/m^2, respectively, lower than any previous measurement and inconsistent with density functional theory (DFT) surface energy calculations of 3.46 and 2.88 J/m^2. However, in an inert gas environment, we measure values of 3.5 +/- 0.2 and 2.9 +/- 0.2 J/m^2, consistent with DFT, that suggest a previously undetected stress corrosion cracking scenario for Si crack initiation in room conditions. This is fully confirmed by hybrid quantum-mechanics–molecular-mechanics calculations.
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机译:在室温和湿度下评估(110)[1-10]和(111)[11-2]裂解体系在硅中的裂解能的断裂实验得出2.7 +/- 0.3和2.2 +/- 0.2 J / m ^ 2分别低于任何先前的测量值,并且与3.46和2.88 J / m ^ 2的密度泛函理论(DFT)表面能计算不一致。但是,在惰性气体环境中,我们测得的值分别为3.5 +/- 0.2和2.9 +/- 0.2 J / m ^ 2,与DFT一致,这表明以前在室温下检测不到Si裂纹引发的应力腐蚀开裂情况。混合量子力学-分子力学计算充分证实了这一点。
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