Song Lin, Shao Anchen, Li Dong, Tian Xuelei, Qiao Zhuhui, Tang Huaguo, Lin Xiaohang
Shandong Laboratory of Advanced Materials and Green Manufacturing at Yantai Yantai 264006 People's Republic of China.
Shandong Ludian Line Equipment Co. Ltd China.
RSC Adv. 2024 Mar 8;14(12):8116-8123. doi: 10.1039/d4ra00853g. eCollection 2024 Mar 6.
In order to investigate the structure of FeAl mesoscopic crystals segregating in liquid state alloys, we have determined their equilibrium structures (Wulff shape) based on the Wulff cluster model. For non-stoichiometric surface terminations, the chemical environment is taken into account through the chemical potential of the constituents. In this case, different cluster shapes change as a function of the chemical environment. In order to model the growth process in more detail, we propose a quasi-static growth model based on the sequential addition of (sub-)monolayers in the most favorable surface directions. Thus, a sequence of different Wulff shapes results in the growth process, as illustrated for the FeAl intermetallic compound. This model is proved preliminarily by calculating the concentration trend of Al/Fe atoms on both Al-terminated and Fe-terminated surfaces, and by simulating the most stable layer adsorbed on these two surfaces. This model might be helpful in analyzing the growth processes including nucleation barriers during nucleation processes theoretically.
为了研究液态合金中偏析的FeAl介观晶体的结构，我们基于Wulff团簇模型确定了它们的平衡结构（Wulff形状）。对于非化学计量比的表面终止，通过组分的化学势来考虑化学环境。在这种情况下，不同的团簇形状会随着化学环境而变化。为了更详细地模拟生长过程，我们提出了一种基于在最有利表面方向上顺序添加（亚）单层的准静态生长模型。因此，在生长过程中会产生一系列不同的Wulff形状，如FeAl金属间化合物所示。通过计算Al端和Fe端表面上Al/Fe原子的浓度趋势，以及模拟吸附在这两个表面上的最稳定层，初步证明了该模型。该模型可能有助于从理论上分析包括成核过程中成核势垒在内的生长过程。
