电沉积铁层晶体结构变化的第一性原理计算

研究了以氯化亚铁为主盐的电镀铁工艺，通过扫描电子显微镜微观形貌分析，铁镀层具有均匀致密结构，铁晶体具有较小的尺寸。通过X射线衍射测试发现，铝基底对铁镀层具有明显的诱导作用，然而随着沉积时间的增加，铁镀层逐渐趋向于Fe（211）晶面择优取向。采用第一性原理计算了不同晶面的表面能，铁晶体不同晶面的表面能依次为Fe（211）＜ Fe（110）＜Fe（200），这很好地解释了Fe（211）晶面择优取向使体系的整体能量降低，有益于铁镀层的稳定性。

First-principle calculations of crystal structure evolution of electrodeposited iron coating

Iron electrodeposition has been investigated employing ferrous chloride as the main salt. The SEM observation reveals that the iron coating has a uniform and compact surface morphology with a relatively small crystal size. The XRD measurement shows that, the texture of iron crystal is distinctly affected by the crystal structure of aluminium substrate. Meanwhile, the iron crystals tend toward the preferred orientation of Fe(211) crystal face. The first principle based on density functional theory was employed to calculate the surface energy of different crystal faces of iron crystal. According to the calculation, the structural stability of Fe surfaces, increasing in the order Fe(211), Fe(110),and Fe(200), was predicted, which explains why the preferred orientation in the iron coating prepared with electrodeposition technology decreases the surface energy, which is beneficial to the stability of the iron coating.