有序畴界原子结构及其迁移特征的微观相场研究

Microscopic Phase-Field Study on the Atomic Structure and Migration Characteristic of Ordered Domain Interfaces

摘要:

利用微观相场模型研究了DO22 (Ni3V) 相间有序畴界原子层次的结构及其迁移特征。研究表明：界面的迁移性与界面结构有关。界面的迁移过程中，V原子跃迁至最近邻的Ni格点处并与之交换，原子的跃迁行为具有位置选择性。原子跃迁行为的位置选择性使得界面迁移前后界面结构保持不变。界面迁移过程及其特征可以用过渡界面来表征，每一种可迁移界面都按照自有的原子跃迁模式进行迁移，并且在迁移的过程中只形成一种独特的过渡界面，界面迁移过程中的原子跃迁模式是诱导界面迁移的热力学和动力学最优化路径。

Abstract:

Atomic structure and migration characteristics of ordered domain interfaces formed between DO22 (Ni3V) phases were investigated using the microscopic phase-field model. Studies show that the migration ability is related to the atomic structure of interfaces. During the migration of interfaces, V jumps to the nearest Ni site and exchanges with Ni, and the jump of atoms show site selectivity behaviors. The site selectivity behaviors of atom jumps force the atomic structure retaining the same before and after the interface migration. Transition interfaces formed during the migration are employed to denote the migration characteristics of interfaces. Each migratory interface forms only one kind of distinctive transition interface and has its own atom jump mode. The atom jump mode is the optimal thermodynamic and kinetics way to induce the migration of interfaces.