异质界面诱发晶构转变的界面应变机制

Heterointerface induced crystallographic transformation:interfacial strain mechanism

摘要:

异质相界面诱发晶构转变是一种特殊的界面现象,在诸多实验研究中均有发现和报道,但机制不明。本文以Fe/Ni界面为例,对BCC/FCC型异质相界面的原子结构和能量学开展第一性原理计算研究,确定了满足{111}Ni/{110}Fe (K-S)关系的界面精细原子结构,并进一步推断该界面处的晶构转变只在临近界面的Ni(111)原子层。其诱发机制主要是界面应变,而与界面原子磁矩的变化无关。

Abstract:

Heterointerface induced crystallographic transformation, as a very unique interface phenomenon, has been recently reported in several experiment studies, but its origin has not yet been clarified. In this study, taking the Ni(111)/Fe(110) interface as an exemplary case, we investigate the atomic structures, energetic, and the responsible phase transition mechanism of FCC/BCC heterogeneous interfaces from the first principles. The results predicted the most energy favored structure to be {111}fcc/{110}bcc (K-S). The crystallographic transition occurs only within the near-interface Ni layers. The responsible mechanism is mainly due to interfacial commensuration strains, without involving the change of atom magnetic moments at the interface.