文档介绍：
不同终端的渗碳体(001)表面稳定性,结
构和电子特性的第一性原理研究#
高扬,吕知清,傅万堂**
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(亚稳材料制备技术与科学国家重点实验室,燕山大学,秦皇岛 066004)
摘要:从利用密度泛函理论优化后的渗碳体体单胞的四个不同位置切取了八种终端的(001)表面,并对它们
进行了计算,结果表明,若 C 原子暴露在表面的最外层或次外层则该表面弛豫能较大(较大的负值)。分割
线越靠近渗碳体体单胞的内部则越难分割出表面。CF3--终端面较其他的终端面更稳定,也就
是说,最外层拥有 C 原子的表面结构最为稳定。
关键词:第一性原理;终端面结构;渗碳体;表面稳定性;分割能
中图分类号:
Stability, structural and electronic properties of θ-Fe3C (001)
surfaces of different terminations: First-principles
investigation
GAO Yang, LV Zhiqing, FU Wantang
(State Key Laboratory of Metastable Materials Science and Technology, Yanshan University,
Qinhuangdao 066004, China)
Abstract: Eight cementite (001) surfaces of different terminations are cleaved from relaxed cementite
bulk cell, and then are calculated from density functional theory. The results indicate that the
terminations which possess carbon atoms in the outermost or the secondary layer have higher
relaxation energy. The deeper the divided line locates in the cementite bulk cell, the harder the
termination is cleaved. The CF3- - terminations are more stable than others, that means, the
terminations are more stable when it possesses carbon atoms in its outermost layer.
Key words: First-principles study; termination structures; cementite; surface stability; cleavage energy
0 引言
作为碳钢和白口铸铁中主要的强化相,渗碳体主要与铁素体通过 Isaichev [1]、Bagaryatskii
[2]
能[5-7]。因此对于钢中渗碳体的研究不能仅针对其体结构