Al 3p occupied states in Al-Cu-Fe intermetallics and enhanced stability of the icosahedral quasicrystal
Al 3p occupied states in Al-Cu-Fe intermetallics and enhanced stability of the icosahedral quasicrystal
复制标题
DOI：
10.1088/0953-8984/12/37/314
复制
发表时间：
2000-09
期刊：
影响因子：
--
通讯作者：
E. Belin-ferre;V. Fournée;J. Dubois
中科院分区：
文献类型：
--
作者：
E. Belin-ferre;V. Fournée;J. Dubois
本文着重比较了Al- cu - fe金属间化合物晶体态和准晶体态中Al- 3p的占据密度。通过计算该偏分布的两个首矩，分别对应于Al原子对材料的内聚能和由配位数调制的轨道重叠的部分贡献，进行了定量比较。从这些数据，我们得出结论，二十面体准晶体及其近似物在Al-Cu-Fe相图中代表了一个特别增强的稳定性区域。我们将这种效应归因于Al - 3p态在休谟-罗瑟利机制中所起的特殊作用。我们证实，在二十面体结构中，Al 3p和Fe 3d态之间存在较强的杂化，而在二十面体化合物中，与稳定的近似物相比，与Cu 3d态的相互作用较弱。
This paper concentrates on a comparison of Al 3p occupied densities of states in crystalline and quasicrystalline Al-Cu-Fe intermetallics. This comparison is made quantitative by computing the two first moments of this partial distribution, which correspond to the partial contribution of Al atoms to the cohesive energy of the material and to the orbital overlap modulated by the coordination number, respectively. From these data, we conclude that the icosahedral quasicrystal and its approximants represent a region of specifically enhanced stability in the Al-Cu-Fe phase diagram. We assign this effect to the specific role played by Al 3p states in the Hume-Rothery mechanism. We confirm the occurrence of a stronger hybridization between Al 3p and Fe 3d states in the icosahedral structure whereas we point out a weaker interaction with Cu 3d states in the icosahedral compounds as compared to stable approximants.