Centre for Advanced Research of Energy and Materials, Faculty of Engineering, Hokkaido University, N13, W8, Kita-ku, Sapporo, Hokkaido 060-8628, Japan.
Sci Rep. 2011;1:190. doi: 10.1038/srep00190. Epub 2011 Dec 12.
Vacancies and interstitial atoms are primary lattice (point) defects that cause observable microstructural changes, such as the formation of dislocation loops and voids in crystalline solids. These defects' diffusion properties determine the phase stability and environmental resistibility of macroscopic materials under ambient conditions. Although in situ methods have been proposed for measuring the diffusion energy of point defects, direct measurement has been limited. In this study, we propose an alternative in situ method to measure the activation energy for vacancy migration under laser irradiation using a pulsed laser beam from a laser-equipped high-voltage electron microscope (laser-HVEM). We made in situ observations that revealed the formation and growth of vacancy dislocation loops in an austenitic stainless steel during laser irradiation. These loops continued to grow when thermal annealing was performed after laser irradiation at the same temperature. We anticipate that laser-HVEM will provide a new method for investigating lattice defects.
空位和间隙原子是主要的晶格（点）缺陷，会导致可观察到的微观结构变化，例如在晶体固体中形成位错环和空隙。这些缺陷的扩散性质决定了宏观材料在环境条件下的相稳定性和环境抵抗力。尽管已经提出了用于测量点缺陷扩散能的原位方法，但直接测量受到限制。在这项研究中，我们提出了一种替代的原位方法，使用配备有激光的高压电子显微镜（激光-HVEM）中的脉冲激光束来测量激光辐照下空位迁移的激活能。我们进行了原位观察，揭示了在激光辐照过程中奥氏体不锈钢中位错环的形成和生长。当在相同温度下进行激光辐照后进行热退火时，这些环继续生长。我们预计激光-HVEM 将为研究晶格缺陷提供一种新方法。
