Covalent State and the Electronic and Transport Properties of CaCu3Ni4O12: A First-Principles Study

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• 作者：Shuhui Lv ; Xiaojuan Liu ; Hongping Li ; Deming Han ; Jian Meng
• 刊名：Journal of Physical Chemistry C
• 出版年：2011
• 出版时间：February 10, 2011
• 年：2011
• 卷：115
• 期：5
• 页码：2366-2370
• 全文大小：881K
• 年卷期：v.115,no.5(February 10, 2011)
• ISSN：1932-7455

文摘

The structure stability and physical properties of CaCu₃Ni₄O₁₂ have been studied by first-principles calculations. It shows that CaCu₃Ni₄O₁₂ is stable both thermodynamically and mechanically. The electronic structure analysis reveals that the Cu covalence is formally +3 and that the Cu ions have the d⁹L configuration (L: an O 2p hole) that corresponds to the Zhang鈭扲ice singlet state. It is predicted to be a ferromagnetic half-metal, comparable to the metallic character of its isostructural compound of CaCu₃Co₄O₁₂. Electron correlation plays a vital role in stabilizing the half-metallic property of CaCu₃Ni₄O₁₂. The Fermi level shifts toward the middle of the minority-spin gap with the increase of U, demonstrating its stability of the half metallicity against structural distortion. Moreover, it is found that O atoms carry unusual large magnetic moments due to the enhanced exchange splitting with the increase of U. All the predicted properties for CaCu₃Ni₄O₁₂ are comparable with the corresponding existing compound CaCu₃Co₄O₁₂. Therefore, interesting physical properties are also expected from CaCu₃Ni₄O₁₂.