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Migration mechanism of a GaN bicrystalline grain boundary as a model system.

ABSTRACT: Using in situ high-resolution transmission electron microscopy, we have explored migration mechanism of a grain boundary in a GaN bicrystal as a model system. During annealing at 500?°C, the grain-boundary region underwent a decrease in thickness, which occurred by decomposition or sublimation of GaN during annealing at 500?°C coupled with electron-beam sputtering. The decrease in thickness corresponds to an increase in the driving force for migration, because the migration of the grain boundary was driven by the surface energy difference. As the driving force increased with annealing time, the grain-boundary morphology turned from atomically smooth to rough, which is characterized by kinetic roughening. The observations indicate that a grain boundary exhibits a nonlinear relationship between driving force for migration and migration velocity, in discord with the general presumption that a grain boundary follows a linear relationship.

SUBMITTER: Lee SB

PROVIDER: S-EPMC4876465 | biostudies-literature | 2016 May

REPOSITORIES: biostudies-literature

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Migration mechanism of a GaN bicrystalline grain boundary as a model system.

Lee Sung Bo SB Yoo Seung Jo SJ Kim Young-Min YM Kim Jin-Gyu JG Han Heung Nam HN

Scientific reports 20160523

Using in situ high-resolution transmission electron microscopy, we have explored migration mechanism of a grain boundary in a GaN bicrystal as a model system. During annealing at 500 °C, the grain-boundary region underwent a decrease in thickness, which occurred by decomposition or sublimation of GaN during annealing at 500 °C coupled with electron-beam sputtering. The decrease in thickness corresponds to an increase in the driving force for migration, because the migration of the grain boundary ...[more]

PMID: 27210538

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