One-Dimensional Fast Migration of Vacancy Clusters in Metals

• Published in: Science (American Association for the Advancement of Science) Vol. 318; no. 5852; pp. 959 - 962
• Main Authors: Matsukawa, Yoshitaka, Zinkle, Steven J
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 09.11.2007; The American Association for the Advancement of Science
• Subjects: Arrays; Atoms; Clusters; Condensed matter: structure, mechanical and thermal properties; Copper; Crystal defects; Crystallography; Defects and impurities in crystals; microstructure; Exact sciences and technology; FCC LATTICES; Fees; GOLD; Kinetics; Lattice vacancies; MASS TRANSFER; MATERIALS SCIENCE; Metals; MICROSTRUCTURE; Migration; MOLECULAR DYNAMICS METHOD; Nanostructure; Nanotechnology; ONE-DIMENSIONAL CALCULATIONS; Physics; Point defects (vacancies, interstitials, color centers, etc.) and defect clusters; RADIATION EFFECTS; Random walk; Room temperature; Semiconductors; Stacking faults; Structure of solids and liquids; crystallography; TRANSMISSION ELECTRON MICROSCOPY; VACANCIES; Nanometer scale; Stacking fault tetrahedron; Crystal defect motion; Self organization; Transmission electron microscopy; Random walk; One dimensional model; Vacancy cluster; Microstructure; Vacancy migration; Atomic structure
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1148336

The migration of point defects, for example, crystal lattice vacancies and self-interstitial atoms (SIAs), typically occurs through three-dimensional random walk in crystalline solids. However, when vacancies and SIAs agglomerate to form planar clusters, the migration mode may change. We observed nanometer-sized clusters of vacancies exhibiting one-dimensional (1D) fast migration. The 1D migration transported a vacancy cluster containing several hundred vacancies with a mobility higher than that of a single vacancy random walk and a mobility comparable to a single SIA random walk. Moreover, we found that the 1D migration may be a key physical mechanism for self-organization of nanometer-sized sessile vacancy cluster (stacking fault tetrahedron) arrays. Harnessing this 1D migration mode may enable new control of defect microstructures such as effective defect removal and introduction of ordered nanostructures in materials, including semiconductors.