State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083, China.
Mater Sci Eng C Mater Biol Appl. 2013 Oct;33(7):3826-31. doi: 10.1016/j.msec.2013.05.013. Epub 2013 May 14.
The surface energies and work functions of Mg, Ca, and MgCa surfaces are derived by means of first principles calculation, and it is found that the Ca-terminated B2 MgCa surfaces have much lower surface energies than corresponding Mg-terminated surfaces. Moreover, calculations reveal that the adsorption energy of Cl atom on Ca (111) surface is much lower than that on Mg (0001) surface due to a stronger CaCl bond than MgCl, and that for MgCa (110) surface, various possible adsorption of Cl atoms are investigated and the most energetically preferred site is found. In addition, the magnitude of adsorption energies suggest that the corrosion resistance of MgCa (110) surface against Cl atom would be located between those of Mg (0001) and Ca (111) surfaces. The relative stability of various adsorption sites is discussed by means of electronic structures, and the present calculated results are in good agreement with experimental results in the literature.
通过第一性原理计算，推导出了 Mg、Ca 和 MgCa 表面的表面能和功函数，发现 Ca 端 B2 MgCa 表面的表面能比相应的 Mg 端表面低得多。此外，计算还表明，由于 CaCl 键比 MgCl 更强，Cl 原子在 Ca（111）表面上的吸附能远低于在 Mg（0001）表面上的吸附能，对于 MgCa（110）表面，还研究了 Cl 原子的各种可能吸附位置，并找到了最具能量优势的吸附位置。此外，吸附能的大小表明，MgCa（110）表面对 Cl 原子的耐腐蚀性将介于 Mg（0001）和 Ca（111）表面之间。通过电子结构讨论了各种吸附位置的相对稳定性，并且本计算结果与文献中的实验结果吻合良好。
