搜索

x
中国物理学会期刊

Cu台阶面多层弛豫的第一性原理研究

CSTR: 32037.14.aps.59.4911

First-principles study of the multilayer relaxation of Cu stepped surfaces

CSTR: 32037.14.aps.59.4911
PDF
导出引用
  • 采用基于密度泛函理论的第一性原理赝势平面波方法对Cu(311),(511),(331)和(221)四个高指数台阶表面的弛豫结构和弛豫后表面各层的电子特性进行了系统研究.发现四个台阶面的层间弛豫规律依次为-+-…,--+-…,--+-…和---+-…,与其平台-阶梯n(hkl)×(uvw)的表示法2(100)×(111),3(100)×(111),3(111)×(111)和4(111)×(111)中的原子排数n相关,即

     

    Using the pseudopotential plane wave (PPPW) method, we performed first principles calculation for the multilayer relaxations and the electron properties of the high-Miller-index stepped Cu(311), (511), (331) and (221) surfaces, which are expressed by 2(100)×(111), 3(100)×(111), 3(111)×(111) and 4(111)×(111), respectively, in the terrace-step notation, i.e. n(hkl)×(uvw). The interlayer relaxations of them are -+-…, --+-…, --+-… and ---+-…, respectively, which follow the atom-row trend: for stepped Cu surface which has n atom rows in the (100) or (111) terrace, the outermost n-1 interlayer spaces contract, then the n interlayer space expands, and the following n+1 interlayer space contracts again. For the stepped surfaces with the same (hkl)×(uvw), the larger the number of atom rows n in the terrace, the greater the contraction magnitude for Δd1,n. We did not find any indication of anomalous relaxation behavior for Cu(511) and (331) as mentioned in some references. Below Fermi energy level, the density of states of the first layer atom at stepped edge has the largest peak value in higher energy regions and has no peak in lower energy regions, so the first layer atom is most unstable and can be dislodged and peeled off more easily than other surface atoms. For the stepped surfaces with the same (hkl)×(uvw), the curves of the density of states have similar shapes for the atoms at the step edge, at the corner, at the terrace and near the corner, and the atoms under the step edge and near the corner.

     

    目录

    /

    返回文章
    返回