Electronic states and adhesion properties at metal/MgO incoherent interfaces: First-principles calculations
Electronic states and adhesion properties at metal/MgO incoherent interfaces: First-principles calculations
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DOI：
10.1103/physrevb.77.165435
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发表时间：
2008-04-01
影响因子：
3.7
通讯作者：
Shibutani, Yoji
中科院分区：
文献类型：
--
作者：
Matsunaka, Daisuke;Shibutani, Yoji
基于密度泛函理论，我们研究了Cu/MgO（001）和Ni/MgO（001）这两种具有大失配的非共格金属/氧化物界面的界面结构和粘附行为。我们发现界面应变和键合特征是不均匀的，这取决于非相干界面上的局部原子构型。在金属原子位于O原子附近的区域，界面金属层被拉伸到相干位置，金属-O界面键具有共价键和离子键的特征。另一方面，在金属原子位于Mg原子附近的区域，金属层几乎没有应变，原子几何形状保持不相干。金属-镁胶粘剂相互作用是由像电荷电子积累介导的，这在相干界面模型结果中是不存在的。我们还发现，界面应变和金属-镁相互作用对粘附能的影响对于准确估计非相干金属/氧化物界面的稳定性具有重要意义。
We investigate interface structure and adhesion behavior of incoherent metal/oxide interfaces with large misfit, Cu/MgO(001) and Ni/MgO(001), based on the density functional theory. We show that the interfacial strain and bonding characteristics are inhomogeneous, depending on local atomic configurations at the incoherent interfaces. In regions where a metal atom is located near an O atom, the interfacial metal layer is stretched to the coherent positions and the metal-O interfacial bond has a covalent and ionic bonding character. On the other hand, in regions where a metal atom is situated near a Mg atom, the metal layer is hardly strained and the atomic geometry remains incoherent. The metal-Mg adhesive interaction is mediated by the image-charge electron accumulation, which is absent in the coherent interface model results. We also find that effects of the interfacial strain as well as the metal-Mg interaction on the adhesive energy are significant for accurate estimation of the stability of incoherent metal/oxide interfaces.